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ivrir 


THE  POTATO 


A  PRACTICAL  TREATISE  ON  THE  POTATO, 
ITS  CHARACTERISTICS,  PLANTING,  CUL- 
TIVATION, HARVESTING,  STORING, 
MARKETING,  INSECTS,  AND  DISEASES 
AND     THEIR    REMEDIES,     ETC.,     ETC. 


SAMUEL   ERASER 

Assistant  Agronomist,  Cornet/  University 


ILLUSTRJTED 


NEW    YORK 

ORANGE    JUDD    COMPANY 
1905 


Copyright,  1905 
BY  ORANGE  JTDD  COMPANY 


To 

%<}^mt6  ^cott  (Borbcn 

WHOSE  LIFE  AND  WORK  ARE  AN 
INSPIRATION  TO  MANY 


PREFACE 


Thk  literature  issued  on  the  subjedt  of  potatoes 
during  the  past  three  hundred  years  would  form  a  large 
library,  many  works  having  been  published  in  the 
United  States,  the  United  Kingdom,  France,  Germany, 
and  other  countries.  It  is  safe  to  say  that  no  plant  has 
aroused  a  deeper  interest  than  '  *  the  noble  tuber. ' '  Its 
very  existence  to-day  is  largely  due  to  the  efforts  of 
enthusiasts.  Several  of  the  older  writers  were  keen 
observers  and  acquainted  intimately  with  the  history 
and  character  of  the  potato,  and  modern  authors  in- 
clude the  names  of  men  who  are  eminent  in  the 
scientific  world.  The  vast  amount  of  research  and 
demonstration  carried  out  by  the  experiment  stations 
of  this  country  during  the  past  ten  years,  and  the  fadl 
that  every  station  has  done  something  in  this  line,  show 
the  breadth  of  the  subjedt  and  furnish  material  hith- 
erto unobtainable.  The  excellent  research  work  now 
being  carried  on  in  Europe,  especially  in  France,  Ger- 
many, etc.,  and  more  recently  established  in  Ireland, 
indicates  a  demand  for  more  information  about  this 
crop.  We  feel  that  the  ".science  of  agriculture"  is 
a  reality  ;  that,  like  every  past  generation,  we  are  on 
the  eve  of  great  discoveries;  that  something  of  the 
laws  governing  plant  nutrition  and  growth  will  shortly 
be  revealed,  that  we  may  be  able  to  prevent  rather  than 
cure  the  troubles  which  assail  our  plants.     To  be  of 


Vlll  PREFACE 

any  use,  scientific  research  must  be  rigidly  accurate  in 
its  observ^ation  and  merciless  to  fallacy  in  logic.  Once 
a  principle  is  proven  it  is  of  no  use  unless  applied,  and 
the  man  to  apply  it  is  the  farmer. 

At  the  present  time  it  behooves  us  to  divest  our- 
selves of  prejudice,  whether  of  tradition  or  custom, 
which  might  tend  to  warp  our  judgment  and  treat  as 
debatable  assumptions  which  long-established  associa- 
tion have  made  shameful  to  doubt,  but  which,  undis- 
turbed, would  make  the  discovery  of  truth  impossible. 
To-day  theories  are  no  longer  revered  because  our 
fathers  believed  in  them.  The  search-light  of  all- 
prying  Science  illuminates  the  whole  field  of  agricul- 
ture, and  has  led  men  to  doubt  and  call  in  question 
even  truth  itself,  in  order  that  they  might  expose  those 
things  which  are  not  true.  It  is  by  this  means  alone, 
by  this  attitude  of  questioning  all  statements  and 
theories,  both  the  truth  and  the  untruth  alike,  that  we 
can  form  a  just  estimate  of  what  is  true.  That  which 
cannot  .stand  the  fire  may  rightly  be  esteemed  dross. 

In  this  book  the  endeavor  has  been  to  colledt  many 
scattered  fa(5ls  from  many  sources,  and  present  these — 
along  with  experience  derived  by  growing  potatoes  for 
several  years,  commercially  and  experimentally,  in  two 
continents — in  the  hope  that  these  data  will  be  of  value 
to  the  reader. 

Samuel  Fraser. 

Cornell  University, 
Ithaca,  N.  Y.,  1905 


JVo/f.— With  the  exception  of  Figs.  26,  27,  28,  29,  30,  31,  43,  and  44,  which 
were  kindly  loaned  by  the  makers  of  these  implements,  and  those  in  which 
credit  is  given  in  the  text,  all  illustrations  have  been  prepared  by  the 
Author. 


CONTENTS 


CHAPTER  I 

PAGES 

History  and  Botany 1-7 

CHAPTER  II 
Some   Conditions   Influencing   Growth 

AND  Development 8-16 

Influence  of  Light  on  Yield,  8;  Amount  of  Mois- 
ture, 8;  Respiration,  9;  Influence  of  Tempera- 
ture on  Respiration,  9;  Influence  of  Temperature 
on  Growth,  10;  Potato  Roots,  10;  Influence  of 
Depth  of  Planting  on  Roots,  15;  Blossoming, 
Tuber  Formation,  and  Hilling,  16. 

CHAPTER  HI 
Soils 17-25 

Best  Soils,  and  Reasons  why  Certain  Soils  are 
Better  than  Others,  17;  Influence  of  Soil  on 
Different  Varieties,  19;  Subsoiling,  20;  Prepara- 
tion of  the  Soil,  21;  Surface-fitting  Tools,  23. 

CHAPTER  IV 
Rotation 26-29 

CHAPTER  V 
Manuring  and  Fertilizing 30-50 

Object,  30;  Influence  of  Nitrogen,  31;  Influence 
of  Potash,  32;  Sources  of  Potash,  33;  Influence 
of  Phosphoric  Acid,  34;  Influence  of  Calcium,  35; 
Barn  Manure,  36;  Function  of  Fertilizers,  39; 
Purchasing  and  Applying  Fertilizers,  42;  Value, 
43;  Unit  Value,  44,  Purchasing,  44;  Valuing 
Barn  Manure,  44;  Mixing  Fertilizers,  46;  Ap- 
plying Fertilizers,  48;  Water  Requirement,  48. 


X  CONTENTS 

CHAPTER  VI 

PAGES 

Considerations  of  Seed 51-69 

Source  of  Seed,  51;  Management  of  Seed  Previ- 
ous to  Planting,  53;  Sprouting  Potatoes,  54; 
Sprouting  Trays,  60;  Whole  vs.  Cut  Sets,  60; 
Time  to  Cut,  61;  Size  of  Seed,  61;  Amount  of 
Seed  per  Acre,  63;  Relative  Value  of  Bud  and 
Stem  Ends  and  the  Middle  of  the  Tuber,  66; 
Viability.  66. 

CHAPTER  VII 
Varieties 70-90 

Selecting  a  Variety,  70;  Cooking  Quality  and 
Flavor,  70,  72;  Yield,  70,  74;  Ability  to  Resist 
Disease,  71,  76;  Color  of  Skin  and  Tuber,  71,  76; 
Nature  of  the  Skin,  71,  78;  The  Shape.  71,  78; 
Depth  and  Frequency  of  Eyes,  71,  79;  Time  of 
Maturity,  71,  79:  The  Haulm,  71,  80;  The  Leaf, 
71,  81;  The  Vigor  of  the  Variety,  71,  82;  Second 
Growth,  71,  85;  Trueness  to  Type,  72,  85;  Test- 
ing Varieties,  86;  The  Relationship  of  Variety 
to  Soil,  87;  The  Most  Popular  Varieties,  87. 

CHAPTER  VIII 
Planting 91-104 

Distance  Apart,  91;  Depth  of  Planting,  93;  Influ- 
ence of  Depth  of  Planting  on  the  Depth  at  Which 
Tubers  Form,  94;  Influence  of  Depth  on  Quality, 
96;  Date  of  Planting,  96;  Influence  of  Late  and 
Early  Planting,  97;  Methods  of  Planting,  97. 

CHAPTER   IX 
Management  of  the  Growing  Crop.     .  105-110 

Cultivation,  105;  Systems  of  Culture,  106;  Hills, 
106;  Drills,  106;  Level  Culture,  107;  Method  of 
Cultivation  and  Tools  Used,  107;  Mulching,  xio. 


CONTENTS  XI 

CHAPTER  X 

'  PAGES 

Obstructions  to  Growth  and  Develop- 
ment     111-127 

Influence  of  Season  and  Climate,  iii;  Weeds, 
112;  Diseases  Due  to  Parasitic  Fungi  and  Bacte- 
ria, 112;  Late  Blight  or  Rot,  112;  Early  Blight 
or  Leaf  Spot  Disease,  118;  Potato  Rosette,  118; 
Scab/  119;  Diseases  in  Storage,  121;  Wet  Rot, 
121;  Dry  Rot,  122;  Stem  Rot  or  Bundle  Blacken- 
ing, 122;  Bacterial  Diseases,  122;  Insects,  123; 
Flea-beetle,  123;  Potato  Bug,  124;  Potato  Worm, 
125;  Potato  Stalk  Weevil,  126;  Grasshoppers,  126; 
June  Bug,  126;  Wireworms,  127;  Striped  Blis- 
ter Beetle,  127;  Arsenical  Poisoning,  127. 

CHAPTER  XI 
Sprays  and  Spraying 128-142 

Fungicides,  128;  Bordeaux  Mixture,  128;  Mixing, 
129;  Testing  Bordeaux  Mixture,  130;  Strength 
of  Solution,  130;  Bordeaux  Dust  or  Dry  Bordeaux 
Mixture,  130;  Washing  Soda  and  Copper  Sul- 
phate Mixture,  131;  Benefits  from  Use  of  Bor- 
deaux Mixture,  131;  Time  of  Spraying,  134; 
Number  of  Sprayings,  134  ;  Insecticides,  135  ; 
Paris  Green,  136;  Lead  Compounds,  137;  Arsenic 
and  Lime,  138;  Cost  of  Spraying  and  Profits  De- 
rived, 139;  Spraying  Machines,  140. 

CHAPTER   XII 
Harvesting 143-146 

Digging,  143;  Methods  of  Digging,  143;  Diggers, 
144. 


XU  CONTENTS 

CHAPTER  XIII 

PAGES 

Storing • 147-152 

Piles,  147;  Cellars,  149;  Construction  of  Cellars, 
149;  Ventilation  and  Temperature,  150;  Losses 
in  Storage,  151. 

CHAPTER   XIV 

Production,  Transportation,  and   Mar- 
kets  153-165 

Factors  Influencing  Farm  Prices,  157;  Modes  of 
Selling,  159;  Local  Markets,  159;  Distant  Mar- 
kets, 160:  Commission  Rates,  160;  Grading,  162; 
Packages,  162;  Barrels,  162;  Bushel  Boxes,  164. 

CHAPTER   XV 

Chemical     Composition      and     Feeding 

Value 166-170 

Composition,  i66;  Digestibility,  i6S;  Feeding 
Value,  168;  Cooking,  169;  Uses,  170. 

CHAPTER   XVI 
Breeding  and  Selection 1 71-177 

Propagation  and  Breeding,  171;  Selection,  175. 

Appendix 179-180 

Spray  Calendar,  178;  Seed  Treatment,  179. 

Index .  i8i 


ILLUSTRATIONS 


FIG.  PAGE 

Spraying  in  a  New  York  Potato  Field  .   Frontispiece 

2  Copy  of    Engraving  of    the    Virginian    Potato    from 

Gerard's  "Herbal,"  1636 2 

3  Sectional  View  of  Potato  Flower 4 

4  Tuber,  Showing  the  Arrangement  of  the  Eyes     .     .  6 

5  Potato  Plant,  Showing  Tubers  (Viewed  from  Above)  12 

6  Potato  Plant,  Showing  Tubers  and  Roots  (Side  View)  13 

7  A  Useful  Type  of  Spring-tooth   Harrow 22 

8  A  Disk  Harrow ,     .     .     .  23 

9  A  Double-action  Cutaway  Harrow 24 

10  The  Influence  of  Lime  Upon   Potatoes 36 

11  Potato  Tray  for  Storing  and  Sprouting  Seed  ...  53 

12  Potato     Planted     Four    Inches    Deep,    Showing    its 

Growth  and  Development  of  Tubers 55 

13  Seed   Potatoes  Sprouted  for  Use  in  the   Planter   ,     ,  56 

14  Seed  of  Early  Potatoes,  Sprouted  for  Hand   Planting  56 

15  Seed  Potatoes,  Showing  Weak,  Long  Sprouts  ...  57 

16  Diagram,   Showing    the    Stand   of    Twenty     Plats    of 

Carman  No.   3   Potatoes 6S 

17  Diagram,    Showing     the     Stand    of    Thirty-six     Plats 

of  Early  Trumbull   Potatoes 68 

18  Section  of  a  Tuber  of   Poor  Cooking  Quality   ...  72 

19  Section  of  a  Tuber  of  Good  Cooking  Quality  ...  73 

20  Three    Varieties    Differing  in  the  Character   of    Net- 

ting of  the  Skin 77 

xiii 


xiv  ILLUSTRATIONS 

FIG.  PAGE 

21  Three  Favorite  Shapes  of  Potatoes 79 

22  Potato  Plant,  Showing  Upright  Haulm So 

23  Potato  Plant,  Early  Variety,  Showing  Dwarf  Haulm  92 

24  The  Modern  Method  of  Planting  Potatoes  ....  98 

25  Planting  by   Hand 99 

26  Sectional  View  of  the  Aspinwall   Potato  Planter.     .  100 

27  Aspinwall  Potato  Planter  (Side  View) loi 

28  The  Robbins  Improved  Planter 103 

29  Platform  of  the  Robbins  Improved  Planter           .     .  104 

30  Halleck  Expansible  Weeder 107 

31  Five-tooth  Cultivator,  with   Hiller  Attachment      .     .  108 

32  A  Useful  Two-horse  Cultivator 109 

33  One-horse  Spring  Tooth  Cultivator no 

34  Section    of    Potato    Leaf,    Showing    the    Parts    and 

Mycelium  of  Blight  {Phytophthora  infestans)      .     .  114 

35  Maturation   of   a    Spore    Sac   and    Germination  of   a 

Spore  of  Rot  (P.  infestans) 115 

36  Longitudinal    Section  of  a  Potato  Stalk,  Showing   a 

Germinating  Spore  of  Rot  {P.  infestans)  .     .     .     .  116 

37  The  Germinating  Tube  of  a  Spore  of  Rot  (P.  infes- 

tans) on  a  Leaf 117 

38  Tubers  with  and  without  Scab 120 

39  The  Cucumber  Flea-beetle  {Crcpidodera  Epitrix  cucti- 

mcris) 123 

40  Leaflet  of    Potato,  Showing  Over  a  Hundred    Holes 

Made  by  Flea-beetles 123 

41  Sprayed    and    Unsprayed    Portions   of   a   New    York 

Potato  Field 133 

42  A  Suggestive   English  Spraying   Machine      ....  140 

43  The  Reuther   Potato  Digger 145 

44  The  Hoover  Digger 146 

45  Potato  Shovel 147 


ILLUSTRATIONS  XV 

FIG.  PAGE 

46  Storing  Potatoes  in  Pits 148 

47  Showing  the    Distribution    of    Potato    Production    in 

the  United  States  in  1899  • ^54 

48  Showing  the   Distribution  of  the  Area  in  the  United 

States  in    Potatoes  in   1S99 155 

49  Grading  and  Barreling  Potatoes  for  Market     .     .     .  163 

50  Potato    Flower,   with    Calix   and    Corolla     Removed, 

Showing  Anthers  and  Stigma 173 

51  Pistil  of  Potato  Flower,   Showing   Parts 174 


ABBREVIATIONS   USED 


U.  S.  D.  A. — United  States  Department  of  Agriculture,  in 
connection  with  reports  or  bulletins. 

E.  S.  R.,  V:33 — Experiment  Station  Record,  Volume  V., 
page  33.  Issued  by  the  United  States  Department  of 
Agriculture,  Office  of  Experiment  Stations. 

Experiment  Stations  in  the  various  States  are  designated  by 
the  common  abbreviation  for  the  State — as,  "Wis.": 
Wisconsin.  Where  there  are  two  stations  in  a  State, 
the  particular  one  is  designated — as.  New  York  (N.  Y.) 
Cornell.  The  number  of  the  bulletin  follows.  Some 
States  issue  their  bulletins  in  volumes,  thus:  Tenn.  Bui., 
Vol.  XI.,  I.,  p.  116 — Tennessee  Bulletin,  Volume  XI., 
No.  I.,  page  116. 

Pa.  D.  A. — Pennsylvania  Department  of  Agriculture.  State 
Departments  of  Agriculture  are  abbreviated  in  this 
manner. 

Can.  Exp.  Farms  Report,  1901,  p.  117 — Canada  Experi- 
mental Farms  Report  for  1901,  page  117. 

Ont.  Agr.  Col.  and  Farm  Report,  1898,  p.  158— Ontario 
Agricultural  College  and  Farm  Report  for  1898,  page 
158. 

Hort.  Trans.,  Vol.  I. — Horticultural  Transactions  of  Eng- 
land, Vol.  I. 

Nat.  His.  of  Car. — Natural  History  of  Carolina.  By  Mark 
Catesby,  F.R.S.     Second   Edition.     London. 

Proc.  Assoc.  Prom.  Agr.  Science — Proceedings  of  the 
Association  for  the  Promotion  of  Agricultural  Science 
(America). 


THE    POTATO 


CHAPTER  I 
HISTORY   AND    BOTANY 

The  potato  {Solanioii  ticbcrosum),  also  called  "  white 
potato,"  "Irish  potato,"  "English  potato,"  or 
"round  potato,"  is  a  native  of  the  elevated  valleys 
of  Chili,  Peru,  and  Mexico,  one  form  of  it  being  found 
as  far  north  as  Southern  Colorado.  The  wild  potatoes 
of  Chili  differ  from  the  cultivated  form,  in  that  they 
produce  seed-balls  more  freely. 

Tobacco,  tomato,  egg-plant,  capsicum,  henbane,  and 
belladonna  all  belong  to  the  potato  family,  but  of 
this  large  family  of  1 600  species  but  six  bear  tubers. 
Some  of  these  latter — as,  Darwin's  potato  {Solarium 
viaglia) — were  thought  to  have  some  value  for  cross- 
ing to  produce  a  blight-proof  new  race,  but  so  far 
success  has  not  been  attained  in  the  latter  respedl.  A 
variety  of  Solanum  commersoni,  another  tuber-bearing 
plant,  is  now  being  boomed  in  Europe  as  a  substitute 
for  the  common  potato.  The  Arizona  wild  potato 
{Solanjwi  jamesii)  has  been  grown  for  many  years  in 
this  country  in  various  places,  but  its  tubers  are  small 
and  of  little  value.  The  Mexican  or  Central  American 
potato  (^Solarium  tuberosum  var.  boreale)  is  found  native 
in  Colorado. 


^.g^^^ 

T^^'' 


THE    POTATO 


fig.  2 — copy  ok  engraving  ok  the  virginian  potato  in 
Gerard's  "  herbal,"  printed  in  1636 

(Compare  with  photograph,  Figs.  5,  6.)    In  England  the  name  Virginian 
potato  was  used  to  designate  its  source. 


The  potato  was  probably  introduced  into  that  part 
of  the  United  States  now  known  as  Virginia  and 
North  Carolina  between  the  middle  and  close  of  the 
sixteenth  centur}'.  It  is  claimed  that  in  1586  colonists 
returning  from  Virginia  probably  took  the  potato  with 


HISTORY    AND    BOTANY  3 

them  to  England.  The  Spanish  had  previously  carried 
it  to  Europe.  Gerard's  "  Herbal,"  published  in  1597, 
describes  the  potato,  and  the  edition  published  in  1636 
contains  a  woodcut  representing  the  potato  as  it  ap- 
peared about  three  hundred  3-ears  ago  (Fig.  2).  The 
potato  was  more  readily  appreciated  in  this  country 
than  in  Europe,  and  by  the  year  1722  it  was  a  common 
article  of  food  among  the  whites  and  Indians  in  Vir- 
ginia and  Carolina.'  In  Europe,  with  the  exception 
of  Ireland,  potato  growing  made  little  progress  until 
the  middle  of  the  eighteenth  century. 

The  potato  {Solaiuun  tuberosum)  is  an  annual,  but 
is  virtually  perennial  by  means  of  its  tubers.  It  has 
smooth,  generally  solid,  more  or  less  quadrangular, 
herbaceous  stems,  which  often  attain  a  hight  of  two  to 
five  feet.  The  stems  are  often  furnished  with  membra- 
nous wings  at  their  angles,  and  bear  compound  leaves 
formed  of  oval  leaflets,  between  which  are  often  found 
small,  leafy  growths.  The  flowers  (Fig.  3 )  are  borne  in 
clusters,  and  have  an  entire,  wheel-shaped,  five-pointed 
corolla,  varying  in  breadth  from  one  to  one  and  a  half 
inches,  and  in  color  from  pure  white  to  purple.  It  is 
often  claimed  that  many  varieties  do  not  flower,  and  of 
those  which  do  a  great  number  never  bear  fruit.  This 
dearth  of  fruit  is  generally  attributed  to  lack  of  pollen. 
In  many  varieties  the  stamens  have  degenerated,  or  do 
not  open  to  let  the  pollen  out."  Conditions  .seem  to 
have  an  influence,  as  a  variety  may  bear  abundance  of 
pollen  and  mature  seed  in  one  distridl,  but  not  in 
another  in  the  same  year. 


'  "Nat.  His.  of  Carolina,"  by  Mark  Catesby,  F.R.S.,  2d  ed.      2  Halstead, 
Proc.  .\ssoc.  Prom.  Agr.  Science,  1888,  p.  33,  "  Potato  Flowers  and  Fruit." 


4 


THK   POTATO 


The  idea  is  prevalent  that  potatoes  do  not  bloom  so 
freely  now  as  formerl^^  The  fadls  do  not  tend  to  con- 
firm this.  Mark  Catesby,  who  was  in  this  country  in 
1722   and   1726,   wrote  that   "  in  Virginia  and  to  the 


FIG.   3 — SECTIONAL    VIEW    OK    I'OTATO    FLOWER 

(Diagrammatic)  ,■ 

a — Ovar>'.  b — Ovules,  which  finally  become  seeds,  c — Calyx,  made  up  of 
green-colored  leaves,  d — Stigma.  The  pollen  attaches  itself  at  this  place. 
^— Style,  down  which  the  pollen-tube  passes  to  the  ovary  and  ovules. 
p — Petals,  white  to  purple  in  color,  i — Stamens.  The  thick  upper  portion 
bears  the  pollen,  and  is  known  as  the  anther. 


north  thereof,  they  [potatoes]  are  annuals,  and  produce 
no  flowers,  while  in  Carolina  and  the  Bahama  Islands 
they  produce  flowers."  Many  varieties  existed  at 
that  time,  particularly  in  Virginia,  and  five  kinds  were 
common — the  Common,  Bermudas,  Brimstone,  Carrot, 


HISTORY    AND    BOTANY  5 

and  Claret  potatoes.  The  Bermuda  potato  was  the 
only  one  that  had  a  white  flower,  the  flowers  of  all  the 
other  kinds  being  purple.  This  was  the  only  variety 
that  had  a  white  skin,  and  was  white  fleshed.  It  was 
round  in  shape,  more  tender,  and  more  delicate  to  raise 
than  the  others,  and  did  not  keep  so  well.' 

George  Don,  in  1831,  enumerates  several  English 
early  varieties,  and  says  that  ' '  none  of  the  above  sorts, 
when  true,  produce  blossoms."  * 

At  Wyoming  Experiment  Station,'  in  1895,  out  of 
56  varieties  grown  14  did  not  bloom,  but  in  1896  but  4 
varieties  failed  to  bloom  out  of  56,  and  only  one  va- 
riety. Blue  Victor,  failed  to  bloom  in  one  of  the  two 
years.  In  other  parts  of  the  State  all  the  varieties 
grown  came  into  bloom.  In  New  York,  during  1904, 
the  variety  Blue  Vidlor  was  profuse  in  its  bloom,  and 
bore  abundance  of  seed-balls.  Out  of  300  varieties  I 
have  followed  closely,  having  grown  many  for  several 
years,  I  find  that  it  is  seldom  that  a  variety  will  not 
bloom  at  some  time  in  its  life,  and  I  am  sure  that  many 
of  the  heaviest-yielding  varieties  bloom  as  freely  as 
those  of  inferior  merit.  At  Wyoming  Experiment 
Station  the  ten  heaviest  jdelding  varieties  all  came  into 
bloom  both  in  1895  and  in  1896,  in  experiments  con- 
ducted in  various  parts  of  the  State. 

The  fruit,  or  seed-ball,  is  a  globular  or  short  oval 
berry,  either  green  or  green  tinged  with  violet,  brown, 
purplish,  or  yellowish  in  color,  and  from  three-quar- 
ters to  one  and  a  half  inches  in  diameter.     It  contains 


>  "Nat.  His.  of  Carolina,"  by  Mark  Catesby,  F.R.S.,  2d  ed. 
2  Don's  "Gardener's  Dictionary,"  1831-S,  Vol.  IV.,  pp.  40x5-406. 
*  Wyo.  Bui.  32,  pp.  54-63. 


THE   POTATO 


small  white  kidney-shaped  seeds  embedded  in  the  midst 
of  a  green  and  very  acrid  pulp  (Fig.  3).  These  seeds 
are  sown  for  the  purpose  of  raising  new  varieties. 

The  main  vertical  underground  stem  varies  in  length 
with  the  depth  of  planting.  This  stem  branches  at  in- 
tervals, and  each  branch  enlarges  at  the  end  to  form  a 
tuber  (Fig.  12).  Usually  from  two  to  four  roots  start 
from  the  vertical  underground 
stem  at  the  base  of  each  tuber- 
l)earing  branch,  but  roots  may 
start  where  such  branches  are 
absent.  This  charadleristic 
growth  may  be  seen  by  grow- 
ing a  potato  in  a  barrel  half 
full  of  soil  and  manure,  and 
watering  it  well;  then,  as  the 
stem  grows,  place  soil  round  it, 
thus  increasing  the  length  of 
the  underground  portion  and 
the  number  of  tuber-bearing 
branches.  The  tubers  may  be 
formed  above  ground,  and 
whenever  thej-  are  abundant 
in  the  axils  of  the  leaves  there 
are  few  or  none  below  ground. 

The  tuber  is  an  underground 
stem,  and  the  eyes  on  it  are 
equivalent  to  the  leaf  buds  on  a  stem  of  a  young 
peach  or  ailanthus.  They  are  arranged  more  or  less 
spirally  in  both  cases  (Fig.  4).  From  the  eye  a  num- 
ber of  buds  may  start;  hence,  in  the  case  of  new  and 
expensive  varieties,  the  tubers  may  be  split  through  the 


FIG.  4 — KIDNEY-SHAPED 

I'OTATO  {Does   Pride) 

Showing  the  alignment  of 
the  eyes,  and  that  the  ter- 
minal buds  tend  to  start 
first.  Note  the  short,  thick, 
desirable  shoots. 


HISTORY   AND    BOTANY  7 

ej-es,  if  desired,  and  a  shoot  obtained  from  each  half. 
As  each  shoot  sets  a  root  it  may  be  broken  off  and  trans- 
planted, and  another  may  start.  By  these  means  and 
great  care  a  pound  of  seed  tubers  has  been  made  to 
yield  2,558  pounds  of  potatoes  in  one  season. 


Historical  Note. — The  early  history  of  the  potato  is  obscure. 
The  most  authentic  information  I  have  secured  is  that  Sir 
Robert  Southwell,  the  President  of  the  Royal  Society  of  Eng- 
land, at  the  meeting  held  December  13,  1693,  stated  that  the 
potato  was  brought  into  Ireland  by  his  grandfather,  who  ob- 
tained tubers  from  Sir  Walter  Raleigh,  after  the  return  of  his 
expedition  from  Virginia.  This  was  in  the  year  1584.  It  is 
now  believed  that  Sir  Walter  Raleigh  fitted  out  this  expedi- 
tion, but  did  not  lead  it  personally,  and  never  was  in  Virginia. 
■  Timbs'  "Curiosities  of  History,"  page  233,  places  the  date 
of  its  introduction  to  the  British  Isles  as  15S6. 


CHAPTER  II 

SOME    CONDITIONS    INFLUENCING    GROWTH 
AND    DEVELOPMENT 

It  is  common  knowledge  that  a  certain  amount  of 
heat  and  an  adequate  supply  of  air  and  moisture  are 
essential  for  plant  growth.  All  plants  that  have  green 
leaves  require  light,  in  addition,  to  enable  them  to  as- 
similate carbon  dioxid  from  the  air,  dissociate  it  into  its 
component  parts,  and  elaborate  the  carbon  into  such 
complex  substances  as  starch,  sugar,  and  other  carbo- 
hydrates. 

Influence  of  Light  on  Yield. — E.  Pagnoul'  placed 
colored  glass  over  different  potato  plants.  Two  plants 
under  darkened  glass  elaborated  31  and  20  grams  of 
starch  respecfli vely ,  while  those  under  ordinary  glass 
elaborated  170  and  no  grams;  at  the  same  time  plants 
under  normal  conditions  elaborated  223  and  361  grams. 
To  the  favorable  influence  of  abundant  light  this  writer 
attributes  the  large  yield  of  potatoes  in  a  season  when 
the  aggregate  number  of  hours  of  sunshine  is  unusually 
large.  At  Wisconsin  Experiment  Station  coldness  and 
cloudiness  were  believed  to  be  the  cau.ses  of  a  poor 
yield.^ 

The  Amount  of  Moisture. — The  amount  of 
water  the  plant  can  obtain  from  the  soil  is  closely  cor- 


I  E.  S.  R.,  v.,  p. 1 16.      -  Wis.  Report,  1902,  p.  188. 
8 


SOME    CONDITIONS    INFLUENCING    GROWTH  9 

related  with  the  mode  of  development.  If  the  soil  is 
very  dry,  and  particularly  if  the  tuber  is  cut,  the  seed 
tuber  may  be  so  weakened  by  loss  of  moisture  that  it 
cannot  grow.  If  a  tuber  has  access  to  but  a  small 
amount  of  water,  there  will  be  little  or  no  root  devel- 
opment, with  little  formation  of  leaf  shoots,  but  tubers 
will  be  formed.  Advantage  is  taken  of  this  fa (51  when 
small  earl}'  potatoes  are  required,  the  tubers  being 
placed  in  sand,  in  a  cellar,  when  small  tubers  will  form, 
but  none  or  few  leaves.  Under  certain  conditions,  with 
an  abundance  or  excess  of  moisture,  numerous  leaf 
shoots  and  roots  appear,  but  no  tubers.  An  increase 
in  the  supply  of  moisture  in  the  air  has  been  found  to 
favor  the  development  of  leaves  on  the  shoots,  where 
only  scales  were  formed  in  an  insufficient  supply  of 
moisture. 

Respiration. — We  may  say  that  all  plants  breathe 
or  take  in  oxygen  and  give  off  carbon  dioxid.  With 
potatoes  this  is  a  necessary  fundlion,  and  if  checked, 
growth  is  injured.  It  is  probable  that  light  induces 
some  conditions  more  favorable  to  increased  respira- 
tion than  darkness;  hence,  if  the  obje(5t  is  to  store  pota- 
toes, it  will  be  better  to  hold  respiration  at  its  lowest 
point  and  keep  them  in  the  dark.  Respiration  cannot 
go  on  without  force  or  energy,  and  as  this  must  be 
supplied,  at  least  partly,  from  the  tuber,  it  follows  that 
adlive  respiration  will  be  attended  b)^  loss  of  weight, 
and  this  goes  on  very  rapidly  when  the  tuber  sprouts. 

If  we  wish  to  ' '  sprout ' '  tubers,  the  best  conditions 
for  doing  so  are  still  undetermined. 

Influence  of  Temperature  on  Respiration. — 
All  plants  have  a  range  of  temperature  at  which  respi- 


lO  THE    POTATO 

ration  is  normal.  The  minimum,  optimum,  and  max- 
imum temperatures  have  been  ascertained  for  some 
plants.  Young  wheat  plants  will  respire  at  as  low  a 
temperature  as  28°  F. ,  or  below  freezing-point.  The 
optimum  temperature  for  wheat  is  about  104°  F., 
while  that  of  potato  plants  is  about  113°  F.  The 
maximum  for  wheat  is  113°  F. ,  while  that  for  pota- 
toes is  about  131°  F.  In  other  words,  the  potato 
respires  best  at  about  113°  F. ,  but  should  the  temper- 
ature go  above  131°  F.,  the  respiration  will  be  some- 
what less  than  before,  and  the  vitality  weakened ; 
hence,  after  a  hot  spell,  when  the  temperature  exceeds 
the  maximum  for  respiration,  it  is  noticeable  that  the 
potatoes  fail  and  become  more  susceptible  to  the  blight 
or  other  troubles,  owing  to  their  impaired  constitu- 
tion. By  sele(5lion  we  might  procure  plants  of  greater 
vitality,  capable  of  standing  the  higher  temperatures, 
which  would  enable  them  to  be  better  ' '  disease-resist- 
ers,"  Present-day  potatoes  thrive  best  in  a  cool 
climate. 

Influence  of  Temperature  on  Growth. — The 
minimum  temperature  for  germination  of  potato  tubers 
is  about  50°  F. ;  hence,  in  the  Northern  States  early 
planted  tubers  make  little  or  no  growth  unless  planted 
shallow,  and  this  is  not  desirable,  except,  perhaps,  for 
the  earliest  varieties.  It  is  better  to  germinate  the 
tubers  in  the  barn  before  planting,  thus  saving  time 
(see  Chapter  VI.,  "  Sprouting  Potatoes  "). 

Potato  Roots. — Generally  speaking,  far  more  at- 
tention has  been  paid  to  the  stems  and  leaves  of  plants 
than  the  roots,  j-et  in  order  to  cultivate  the  soil  in  a 
rational  manner  it  is  essential  to  know  where  the  roots 


SOME    CONDITIONS    INFLUENCING   GROWTH  I  I 

are,  their  cliara(5ler,  and  requirements.  Examination 
of  the  roots  of  Earl}' Ohio  potatoes,'  made  July  5,  1899, 
forty-three  days  after  planting,  about  the  time  the  crop 
received  its  third  cultivation,  showed  that  at  this  time 
there  was  little  growth  of  fibrous  roots — only  the  skele- 
ton system  supplied  with  numerous  delicate  root  hairs. 
The  seed  tuber  appeared  to  be  sound  and  whole,  but  on 
closer. examination  it  proved  to  be  but  a  shell.  Only  a 
few  eyes  on  the  upper  side  of  each  tuber  produced  shoots; 
thus  one  hill  produced  three  stalks  from  two  eyes,  and 
another  had  seven  stalks  springing  from  five  eyes. 
The  latter  plant  had  more  numerous  but  smaller  roots 
than  the  former.  Twenty-five  small  potatoes  were  set 
on  the  first  plant,  the  largest  of  which  were  the  size 
of  a  large  pea.  At  this  stage  of  development  the  main 
portion  of  the  roots  was  in  the  surface  eight  inches,  a 
few  roots  reached  to  the  depth  of  eighteen  inches,  but 
the  greatest  root  growth  was  in  a  horizontal  diredlion. 
The  roots  from  each  hill  had  already  met  and  interlaced, 
some  having  reached  a  length  of  two  feet,  the  plants 
being  three  feet  apart.  At  six  inches  from  the  hill  some 
of  the  main  lateral  roots  were  but  two  and  one-quarter 
inches  from  the  surface  of  the  ground,  while  midway 
between  the  rows  their  depth  was  barely  three  inches 
from  the  surface. 

Further  examination  of  Early  Ohio  potatoes  seventy- 
two  days  after  planting,  when  the  tubers  were  nearly 
full  size,  showed  that  the  main  root  growth  was  in  the 
upper  foot  of  soil  ;  several  of  the  large  horizontal  roots 
were  within  three  inches  of  the  surface,  and  one  was 
but  one  inch  deep.     Some  of  the  vertical  roots  reached 

■  N.  Dak.  Bui.  45,  p.  541. 


14  THE   POTATO 

a  depth  of  two  and  a  half  feet.  The  deep-growing 
roots  are  very  tender  and  brittle  and  easily  broken, 
differing  in  this  respedl  from  corn  roots.  The  hori- 
zontal roots  send  out  vertical  branches,  which  often 
descend  to  a  depth  of  two  feet  or  more. 

Shallow  tillage,  such  as  hand-hoeing  without  hill- 
ing, retains  all  the  roots.  Moderately  deep  tillage 
with  a  five-tooth  single  horse-cultivator  and  slight 
hilling  destroj-s  pradtically  all  the  surface  roots,  and 
undoubtedly  interferes  seriously  with  the  plant's  de- 
velopment ;  while  with  deep  tillage  nearly  all  the  long 
horizontal  roots  are  destroyed,  and  with  theni  all  their 
numerous  vertical  branch-roots  with  their  intricate 
system  of  fibres  and  root  hairs,  by  which  the  potato 
receives  its  food.  In  very  heavy  soils  it  may  be  wise  to 
plant  potatoes  shallow  and  then  hill  them,  but  in  most 
soils  it  is  better  policy  to  plow  deep,  plant  fairly  deep, 
and  give  shallow  flat  cultivation.  With  deep  tillage 
the  roots  nearest  the  surface  were  at  a  depth  of  seven 
inches,  while  in  the  case  of  those  receiving  shallow 
tillage  the  bulk  of  the  horizontal  roots  were  in  the  sur- 
face seven  inches.  The  hilling  covers  the  potatoes  and 
prevents  them  from  sunburning,  and  this  seems  to  be 
all  the  benefit  received.  The  loss  of  roots  is  very 
hurtful,  and  takes  place  at  a  time  when  the  plant  can 
least  afford  to  suffer  injur}'.  Experiments  conducted 
at  Vermont  Experiment  Station'  show  that  during 
the  last  weeks  of  growth  the  weekly  increase  in  weight 
of  tubers  is  at  its  maximum,  and  that  checks  when  the 
tubers  are  approaching  maturity  depress  the  yield  cor- 
respondingly. 

'  Ver.  Bui.  72,  p.  5. 


SOME    CONDITIONS    INFLUENCING    GROWTH  1 5 

A  sample  of  Early  Ohio  potatoes  taken  ninety  days 
after  planting,  when  the  vines  were  beginning  to  die 
and  the  tubers  were  nearly  ripe,  showed  that  the  roots 
penetrated  to  a  depth  of  over  two  and  a  half  feet.'  The 
branches  from  the  main  lateral  roots  had  reached  about 
as  deep  as  those  immediately  under  the  hill,  and  the 
soil  was  filled  with  roots  to  a  depth  of  about  two  and 
a  half  feet.  The  system  of  rooting  is  similar  to  that  of 
corn,  but  the  plant  is  not  so  good  a  forager,  and  the 
roots  do  not  fill  the  soil  so  completely;  hence,  plants 
can  be  placed  closer  together. 

Late  varieties  have  a  similar  root  system,  but  root 
more  freely,  more  deeply  (a  depth  of  three  and  a  half 
feet  being  common  if  the  soil  conditions  will  permit), 
and  occupy  the  ground  more  completely;  hence,  require 
more  room  than  early  varieties. 

At  Cornell  University,  during  1904,  many  potatoes 
had  horizontal  roots  in  the  surface  inch  of  soil.  All 
of  these  would  be  destroyed  by  moderately  deep  tillage. 

Influence  of  Depth  of  Planting  on  Roots. — 
Generally  speaking,  the  new  potatoes  and  the  roots  start 
out  above  the  seed,  although  if  an  under  eye  of  the 
potato  produces  the  shoot  the  roots  and  tubers  may 
develop  at  the  side  of  the  seed.  Depth  of  planting  has 
some  influence  on  the  depth,  at  which  the  tubers  will 
form,  and  may  have  some  on  the  roots.  The  question 
deser\'es  investigation.  Many  plants  prefer  to  send 
out  their  roots  at  a  uniform  depth  below  the  surface : 
thus,  at  Cornell  University,  wheat,  whether  planted 
six  inches  deep  or  one  inch  deep,  will  send  out  its  per- 


1  N.  Dak.  Bui.  43,  p.  544. 


1 6  THE   POTATO 

manent  roots  about  one  and  a  half  inches  below  the 
surface. 

Blossoming,  Tuber  Formation,  and  Hilling. — 
Potatoes  are  hilled  about  the  time  they  come  into 
bloom,  and  this  is  the  time  that  tuber  formation  is 
beginning.  The  ancestral  tj'pe  of  potato  developed 
seed  about  this  time  and  died  ;  the  tendency  acquired 
by  cultivation  is  to  throw  all  the  reserve  material  into 
tuber  production.  These  reproductive  processes  cause 
a  severe  drain  upon  the  plant's  energies,  and  the  fort- 
night immediately  following  the  blossoming  period  is 
therefore  a  peculiarly  critical  time  for  the  plant,  during 
which  time  its  life  hangs  in  the  balance.  At  this  time 
it  is  subje(ft  to  extreme  heat,  and  may  be  injured;  also 
insedls,  fungi,  etc.,  may  attack  it,  and,  to  add  to  its 
troubles,  cutting  off  a  lot  of  its  roots,  either  just  before 
or  about  this  time,  is  no  doubt  the  common  cause  of  a 
decline  from  which  the  plant  never  recovers.  Even 
tuber  formation ,  without  the  influence  of  other  agen- 
cies, may  cause  a  plant  to  die.  The  importance  of 
studying  the  condition  of  the  plant  at  this  time  will  be 
appreciated  when  it  is  remembered  that  the  entire  crop 
of  salable  tubers  is  formed  after  this  critical  period  is 
past,  and  full  success  with  the  crop  depends  upon  retain- 
ing the  plant  healthy  for  from  one  to  three  months 
after  the  blossoming  period.  During  August,  in  one 
case,'  the  crop  of  potatoes  increased  at  the  rate  of  over 
50  bushels,  or  over  3,000  pounds,  weekly  per  acre. 
The  importance  of  avoiding  checking  growth  prepara- 
tory to  or  during  such  a  time  is  evident. 

1  Ver.  Bui.  72,  p.  5. 


CHAPTER    III 
SOILS 

The  soil  considered  best  is  a  deep,  mellow,  free- 
working  loam,  grading  either  to  a  sandy  loam  or  clay 
loam,  although  the  crop  may  be  raised  on  lighter  or 
heavier  soils,  provided  the  latter  are  drained.  Tile 
drainage  should  be  resorted  to,  if  necessary,  to  reduce 
the  water  table  to  from  3  feet  6  inches  to  4  feet  below 
the  surface. 

Some  reasons  for  seledting  a  light,  sandy,  or  gravelly 
loam  for  the  crop  are  : 

1 .  Such  soils  can  be  worked  early  in  spring,  and  gotten 

ready  for  early  planting,  if  desired  ; 

2.  The  lighter  soil  becomes  warm  more  readily  in  the 

spring  than  a  heavier  soil,  and  germination  of  the 
tuber  and  growth  of  the  plant  proceeds  more 
rapidly  ; 

3.  They  can  be  easily  worked,  and  placed  and  main- 

tained in  good  tilth  without  a  heavy  labor  bill  ; 

4.  The  effects  of  the  manures  and  fertilizers  applied 

are  generally  perceptible  for  a  longer  period  of 
time  than  on  lighter  soils  ; 

5.  The  potatoes  grown  on  such  a  soil  usually  come  out 

bright  and  clean,  smooth  and  of  more  uniform 
size  —  important  fadtors  when  they  go  on  the 
market ; 

17 


1 8  THE   POTATO 

6.  Light  soils  usually  produce  potatoes  of  better  qual- 

ity, because  they  tend  to  shorten  the  growing 
period  by  cutting  off  the  moisture  supply,  and  thus 
forcing  the  potatoes  to  mature  earlier; 

7.  Those  grown  on  well-drained  sandy  loam  soils  usu- 

ally keep  better  than  those   grown  on  stiff  clay 

soils. 
Aroostock  County,  Maine,  is  famous  for  its  potatoes.' 
Its  soil  presents  a  gentl)'  rolling  surface,  and  is  com- 
posed essentially  of  drift  deposited  during  the  melting 
of  the  ice  after  the  ice  age,  and  resting  on  a  stratum 
of  limestone,  which  in  many  places  comes  to  the  sur- 
face. The  soil  partakes  of  the  general  nature  of  drift 
containing  a  considerable  portion  of  sand  and  the  usual 
amount  of  organic  matter.  It  is  peculiarly  suited  to 
potatoes,  because  it  does  not  pack  after  hard  rains  nor 
during  periods  of  drouth.  Its  open  and  porous  nature 
permits  the  free  development  of  tubers  and  the  ramifi- 
cation of  the  roots.  The  soil  was  originally  covered 
with  a  growth  of  hard  and  soft  woods,  consisting  chiefly 
of  maple,  cedar,  birch,  white  poplar,  spruce,  hemlock, 
and  pine.  The  forest  growth  was  dense,  and  in  clear- 
ing large  quantities  of  ashes  were  produced,  which 
fitted  the  virgin  fields  particularly  for  the  produ(5lion 
of  large  crops  of  potatoes.  After  a  few  years  of  culti- 
vation, the  crop-producing  power  of  the  soil  showed  a 
diminution,  and  to-day  applications  of  farm  manures 
and  commercial  fertilizers  containing  a  large  percent- 
age of  potash  are  resorted  to.  Analyses  of  Maine  soils 
show  that  they  are  silicious,  contain  considerable  or- 


1  U.  S.  D.  A.,  Div.  of  Chemistry,  Bui.  58,  p.  5-8. 


SOILS  19 

ganic  matter,  and  are  reasonably  rich  in  lime  and  mag- 
nesia, which  seem  to  be  essential  constituents  of  a  soil 
suited  to  the  growth  of  potatoes.  The  potash  is  also 
in  fair  quantity,  but  not  sufl&cient  to  produce  maximum 
crops.  The  famous  potato-growing  counties  of  Wiscon- 
sin, Portage,  Waushara,  and  Waupaca  had  over  60,000 
acres  in  potatoes  in  1899,  and  these  are  as  important 
to  the  Central  States  as  Aroostock  County,  Maine,  is 
to  the  Eastern  States.  The  soil  is  glacial  drift,  some 
of  it  being  made  up  of  level  deposits  of  sand  and  gravel 
covered  with  a  light  loam.  The  sand  is  usually  un- 
derdrained  by  a  bed  of  coarse  gravel.  Sandy  loams 
prevail.  Clayey  loams  occupy  some  areas,  but  are 
not  prevalent.  The  average  3'ield  is  100  bushels 
per  acre. 

On  lyong  Island,  N.  Y.,  the  chief  potato  soils  on  the 
south  side  of  the  island  are  light  silt  loams  underlain 
either  by  gravel  or  sand,  while  gravelly  till  is  the 
main  type  on  the  northern  side.  The  yields  var}^  from 
80  to  250  bushels  per  acre. 

The  Influence  of  Soil  on  Different  Varieties. — 
Professor  Buffum,'  of  Wyoming  Experiment  Station, 
reported  on  eight  varieties  grown  on  each  of  two  kinds 
of  soil  represented  on  the  experiment  farm.  The  soil 
and  crops  were  treated  alike.  Plat  i  is  bench-land 
above  the  river,  and  is  a  deep  red  colluvial  soil  con- 
taining little  humus.  Plat  2  is  bottom-land  next  the 
river,  and  is  a  black  soil  containing  a  large  amount  of 
humus. 


»  Wyo.  Bui.  32,  p.  6. 


20 


THE   POTATO 
TABLE  1 


VARIETY 

Plal  I 
Yield  per  acre 

Plat  2 
Yield  per  acre 

Increased  yield 
on  Plat  2 

Beauty  of  Hebron 

Early  Maj-flower 

Early  Puritan 

Empire  State 

Late  Puritan 

Pride  of  the  West 

Snowdrop 

White  Elephant 

Lbs. 

9,678 
15,060 
12,702 
15.372 
18.858 

5.040 
14.562 
11,808 

Lbs. 
23.628 
28,842 
32.340 
22,698 
26,742 
23.322 
25,500 
27,990 

Lbs. 
13.950 
13.782 
19,638 
7.326 
7,884 
18,282 
10,938 
16,182 

Average  

12,885 

26,383 

13.498 

The  figures  taken  colle(ftively  show  the  importance 
of  selecfling  a  soil  suitable  for  the  crop  to  be  grown, 
the  yield  being  doubled  on  Plat  2,  while  taken  indi- 
vidually it  is  evident  that  certain  varieties  were  better 
adapted  to  the  environment  than  others.  The  ques- 
tion of  which  variety  will  best  suit  the  environment 
must  be  determined  by  the  grower. 

Subsoiling. — BufTum',  of  Wyoming,  states  that  sub- 
soiling  may  be  recommended  throughout  that  State  for 
potatoes.  The  cost  of  subsoiling  to  a  depth  of  16  inches 
to  18  inches  varied  between  $3.00  and  $6.00  per  acre. 
Hays%  of  Minnesota,  found  it  to  be  expensive  and  not 
profitable  under  most  conditions  in  that  State,  and  that 
it  reduced  the  yields  of  crops  on  land  already  suffi- 
ciently open  and  porous.  In  humid  climates,  if  at- 
tempted, it  is  advocated  that  subsoiling  be  done  in  the 
fall,  to  permit  the  readjustment  of  the  soil  granules 
before  springtime,  so  that  the  moisture  will  be  able  to 
rise  upward    from  the  subsoil,   as   evaporation   takes 


'  Wyo.  Bui.  41,  pp.  20.  21;  Bui.  32,  pp.  7,  8.' 


2  Minn.  Bui.  68,  p.  609. 


SOILS  2  r 

place  at  the  surface,  and  prevent  the  crop  being  de- 
stroyed by  lack  of  moisture.  Injurious  results  from 
subsoiling  in  spring  have  been  noted,  probably  due  to 
the  working  of  the  subsoil  when  it  was  too  wet.  It 
does  not  follow  that  because  the  surface  soil  to  the  depth 
of  eight  inches  is  dry  enough  to  plow  the  subsoil  will 
be,  and  in  many  cases  the  subsoil  has  been  puddled 
by  spring  working,  and  the  supply  of  moisture  from 
below  more  or  less  completely  cut  ofif,  with  disastrous 
results  to  the  crop. 

Preparation  of  the  Soil. — The  ideal  crop  to  pre- 
cede potatoes  is  timber,  but  as  no  rotation  comprising 
this  crop  is  in  use,  the  preparation  given  after  timber 
demands  little  attention.  Potatoes  are  more  commonly 
grown  after  potatoes,  corn,  or  after  clover  or  sod.  In 
such  cases  preference  is  usually  given  to  fall  plowing, 
accomplished  during  Odlober  or  November  until  freez- 
ing prevents  further  work.  Deep  plowing  should  be 
done  in  fall,  because  opportunity  is  then  given  for  the 
storage  of  water  in  the  soil  during  the  winter  and 
when  the  thaw  occurs  in  spring.  If  manure  is  to  be 
applied  it  is  spread  before  plowing,  but,  if  rotted,  it  may 
be  applied  later  and  disked  in.  The  depth  of  plowing 
varies  with  the  soil,  probably  six  inches  or  eight  inches 
being  most  common,  although,  if  the  soil  will  permit, 
eight  inches  to  twelve  inches  will  be  better.  When 
soils  are  deficient  in  humus,  it  is  generally  inadvisable 
to  plow  deeply.  The  humus  content  of  such  soils 
should  be  increased  and  the  depth  of  plowing  increased 
correspondingly,  thus  bringing  the  land  into  a  higher 
state  of  produdlion.  In  some  districfts  where  the  snow 
covers  the  ground  all  winter  the  land  is  harrowed  well 


22 


THE   POTATO 


in  fall  and  left  nearly  ready  for  planting,  thus  facilita- 
ting spring  work.  Where  the  frost  penetrates  deeply, 
or  the  soil  is  apt  to  run  together,  the  land  is  better  left 
rough  plowed  all  winter  and  fitted  in  spring  ;  but  this 
entails  some  loss  of  time,  and  prevents  the  earl}^  plant- 
ing of  potatoes. 

Sometimes  it  is  necessary  to  plow  in  spring,  and  in 
many  cases  it  is  profitable  to  replow  when  a  fall  plow- 


FIG.  7 — A   USEFUL   TYPE   OF    SPKI.NG- i'UOTHED    HARROW 


ing  has  been  given.  Under  such  conditions  a  depth  of 
not  more  than  six  inches  or  eight  inches  is  advised, 
because  plowing  land  is  attended  by  loss  of  moisture, 
and  in  most  cases  the  amount  of  moisture  held  in  the 
?oil  or  supplied  as  rainfall  during  the  growing  period 
is  insufficient  to  insure  maximum  yields  ;  hence,  care 
should  be  taken  to  conserve  all  the  moisture  possible 
by  plowing  judiciously,  making  and  maintaining  a 
mulch  of  the  surface  soil,  thus  checking  evaporation, 


SOILS 


23 


and  by  enriching  the  soil  in  humus  either  by  manuring 
or  a  suitable  rotation.  Humus  affedls  the  physical 
properties  of  the  soil  considerably — among  other  things, 
enabling  it  to  hold  more  moisture  without  injury  to 
the  plants  in  a  wet  time,  and  to  endure  drouth  in  a 


FIG.  8 — AN   EFFICIENT    PULVERIZER;    THE    DISK    HARROW 

dry   time.'     Even   where   irrigation   is   pradliced    the 
above  fa(5lors  cannot  be  economically  negle<fled. 

Surface-fitting  Tools. — The  Acme  harrow  is  one 
of  the  best  tools  for  making  a  soil  mulch  before  the 
crop  is  planted,  and  in  trials  made  by  Sanborn^  was 
shown  to  be  the  most  efficient  type  of  harrow  for  pul- 
verizing soil.  On  stony  land,  or  where  roots  of  trees 
interfere,  the  spring-tooth  harrow  (Fig.  7)  is  preferred 
for  deep  tillage  of  the  soil,  while  under  other  conditions 


'  Minn.  Bid.  6S,  pp.  576-579.       -  Utah  Bui.  4. 


24 


THE    POTATO 


the  disk  harrow.  These  tools  work  deeper  than  the 
Acme  harrow,  and  may  be  used  to  prepare  the  soil  to  a 
depth  of  four  to  six  inches,  which  seems  to  be  as  deep  as 
is  necessary.  Few  farmers  prepare  land  to  this  depth, 
as  it  requires  three  horses  on  a  six-foot  harrow  on  a  loam 
soil.  Two  to  2}4  inches  is  more  common.  Harrows 
differ  in  their  action;  thus,  the  spring-toothed  harrow 


FIG.  9— DOUBLE-ACTION   CUTAWAY   HARROW 

and  the  smoothing  or  spike-tooth  harrow  tend  to  com- 
pact the  soil  while  fining  it,  while  the  disk  type  (Figs. 
8  and  9)  and  Acme  harrows  tend  to  lighten  it  and  make 
it  more  open  when  they  fine  it.  For  potatoes  and  corn 
the  latter  are  preferable,  while  for  wheat  the  former. 
Whatever  tool  is  used  the  land  should  be  well  fitted. 
Few  farmers  prepare  the  land  well  enough,  and  many 


N,  C,  State  CMege 


SOILS  25 

would  find  it  more  economical  and  profitable  to  spend 
another  week  working  the  land  than  to  rush  the  crop 
into  a  badly  prepared  seed-bed.  The  soil  under  the 
plants  and  near  them  cannot  be  touched  when  they  have 
been  planted,  while  wide  tools  may  be  used  before. 


CHAPTER  IV 
ROTATION 

In  some  cases  potatoes  are  grown  continuously  for 
several  j^ears  on  the  same  soil,  but  a  rotation  of  crops 
is  preferable  for  manj^  reasons — among  others,  to  lessen 
the  dangers  of  attacks  of  diseases  and  insects,  and  to 
bring  the  soil  into  a  suitable  physical  condition  for 
growing  this  crop.  Some  rotations  suggested  by 
Wheeler,  of  the  Rhode  Island  Experiment  Station,' 
are  as  follows:  three-year  rotation — potatoes,  winter 
rye,  common  red  clover;  four-year  rotation — corn  on 
clover  sod,  potatoes,  winter  rye,  clover.  This  can  be 
made  into  a  five-year  rotation  by  seeding  timothy' and 
redtop  with  the  clover,  and  leaving  the  mixture  down 
two  years,  thus  reducing  the  labor  bill  to  some  ex- 
tent. Trials  of  these  and  other  rotations  were  made 
on  land  so  poor  that  corn  attained  a  hight  of  but  4 
or  5  inches,  while  the  first  crops  of  salable  potatoes 
were  but  65  bushels  per  acre.  During  later  years, 
with  management  similar  to  that  given  the  first  year, 
and  the  application  of  a  similar  amount  of  fertilizers, 
the  yields  ran  up  to  350  bushels  of  salable  potatoes  per 
acre.  A  common  Maine  rotation  is  a  four-year  course 
of  potatoes,  oats,  clover  and  grass,  the  latter  for  two 
years — it  being  noted  that  clover  thrives  on  good  po- 
tato land.    In  deciding  upon  the  rotation  it  is  important 


1  R.  I.  Bui.  74,  75,  76. 
26 


ROTATION  27 

to  note  the  influence  of  each  crop  upon  the  moisture 
content  of  the  soil  (see  p.  50);  thus,  rye  removes  less 
moisture  from  the  soil  than  wheat.  Oats  draw  heav- 
il}^  upon  the  moisture  content. 

The  potato  crop  is  not  usually  considered  to  be  a 
heavy  water  consumer.  It  leaves  the  soil  in  a  rela- 
tively moist  condition;  hence,  the  wisdom  of  the  Maine 
four-year  course,  in  which  oats  succeed  potatoes. 
This  course  requires  but  one  deep  plowing  in  four 
years,  that  for  the  potatoes,  and  in  this  it  is  econom- 
ical. Peas  use  a  relatively  small  amount  of  water, 
and  would  leave  the  soil  in  good  shape  for  potatoes. 
In  Wisconsin,'  while  potatoes  grown  in  rotation  yield- 
ed 342.8  bushels  per  acre,  a  crop  grown  on  an  old 
alfalfa  sod  yielded  but  277.7  bushels  per  acre,  al- 
though the  rainfall  was  considered  adequate  to  pro- 
duce a  full  crop.  In  some  cases  clover  tends  to 
leave  the  soil  drier  than  some  other  crops,  and  its 
use  as  the  preceding  crop  for  potatoes  may  be  detri- 
mental. In  most  ca.ses,  however,  a  leguminous  crop 
is  the  best  to  precede  potatoes.  In  Florida"  cow-peas 
preceding  potatoes  increased  the  yield  40  per  cent. 
The  Ohio  Station^  found  that  in  the  three-course  rota- 
tion— potatoes,  wheat,  clover — whenever  good  crops  of 
clover  were  grown  the  economy  of  using  nitrogenous 
fertilizers  for  the  potatoes  was  questionable,  thus  show- 
ing that  a  good  rotation  is  equivalent  to  manuring. 
Plowing  under  a  leguminous  crop  is  held  to  be  good 
practice  on  farms  where  an  adequate  supply  of  manure 
is  not  forthcoming  and  little  stock  is  kept;  thus,  a-t  the 


1  wis.  Report,  1902,  p.  1S8.  ^  Fla.  Report,  1900-1901.  p.  26. 

3  Ohio  Bui.  125,  p.  132. 


28 


THE   POTATO 


Maryland  Station,'  plowing  under  a  crop  of  crimson 
clover  increased  the  yield  34.4  bushels  per  acre,  or  50 
per  cent.,  and  the  average  gain  for  two  3'ears  was  27 
bushels  per  acre,  or  45  per  cent.;  the  Storrs^  (Connedl- 
icut)  Station  reports  that  clover  sown  in  corn  at  the 
last  cultivation  had  a  high  value  \vhen  used  to  plow 
under  as  manure  for  potatoes,  even  though  it  only 
attained  a  hight  of  three  or  four  inches ;  in  Germany' 
the  sweet  clover  {Mcli lotus  alba)  is  found  to  be  a  valu- 
able green  manure;  while  in  another  German  experi- 
ment,^ where  clover  was  seeded  in  rye  which  was 
grown  for  grain,  the  clover  being  plowed  under  the 
following  spring,  it  was  noted  that  the  jdeld  of  rye 
was  dimished,  but  the  yield  of  the  succeeding  crop  of 
potatoes  was  increased.  The  yields  of  rj-e  and  potatoes 
were: 

TABLE  II 


CROP 

}  'ield  per  acre  of 
rye,  1892 

Yield  per  acre  of 
potatoes,  1893 

Bushels         Lbs. 

Bushels          Lbs. 

14  44 

15  21 
13                       50 

12                 35 

289                 35 

Rye  alone 

Rye  and  late  sown  red  clover 
Rye  and  early  sown  red  clover 

296                 15 
330                 25 
430                 39 

As  green  manuring  for  poor  sandy  land  on  Long 
Island,  N.  Y.,  Professor  Stone,  of  Cornell  University, 
suggested  sowing  a  bushel  of  cow-peas  and  ten  pounds 
of  crimson  clover  per  acre,  in  July,  with  some  fertil- 


1  Md.  Bui.  38,  p.  58. 
^  E.  S.  R.,  v.,  p.  701. 


2  Conn.  (Storrs)  Report,  1900,  p.  65. 
*  E.  S.  R.,  VI.,  p.  292. 


ROTATION  29 

izers.  The  cow-peas  were  killed  by  the  first  frost,  but 
the  clover  persisted;  the  crowding,  however,  was  such 
that  the  plants  of  neither  crop  got  too  large  before  be- 
ing plowed  under  the  following  spring.  For  farther 
north  a  combination  of  half  a  bushel  of  buckwheat 
and  a  peck  to  half  a  bushel  of  r^^e  per  acre,  sown 
together,  has  given  good  results.  Rape  sown  at  the 
rate  of  four  to  five  pounds  per  acre  is  useful.  Other 
crops  will  suggest  themselves.  In  parts  of  New  York, 
especially  on  heavy  loams,  buckwheat  is  esteemed  as 
the  preceding  crop  for  potatoes.  It  crowds  out  weeds 
and  leaves  the  soil  in  excellent  physical  condition. 


CHAPTER  V 
MANURING   AND    FERTILIZING 

Land  is  manured  and  fertilized  either  to  increase  or  to 
maintain  its  crop-producing  power.  Whether  this  is 
secured  by  the  diredt  effecft  of  the  chemical  ingredients  in 
the  manure  or  fertilizers,  or  by  their  influence  upon  the 
physical  properties  of  the  soil,  or  both,  is  an  unsettled 
scientific  problem,  but  all  agree  that  under  certain  con- 
ditions the  addition  of  manures,  fertilizers,  and  water 
to  the  soil  is  profitable.  Whether  it  will  be  profitable 
on  a  particular  farm  or  field,  and  the  manure,  fertil- 
izer or  combination  of  fertilizers  which  will  be  most 
profitable  to  use,  are  questions  the  grower  must  settle 
for  himself  by  trial.  No  chemical  examination  of  the 
soil  yet  conducted  has  shown  wh}'  two  soils,  apparently 
identical  in  chemical  composition,  should  not  produce 
similar  yields  of  crops.  Experience  has  shown  that 
the  chemical  composition  of  the  soil  is  no  guide  to  its 
crop-producing  power.  Hence,  all  that  can  be  given  in 
this  chapter  is  to  submit  mixtures  of  fertilizers  that 
are  used  and  the  role  the  different  important  ingre- 
dients are  believed  to  play  in  the  plant  economy. 

In  addition  to  water,  which  is  treated  elsewhere, 
four  elements  are  frequently  applied  in  various  chem- 
ical forms  as  fertilizers — nitrogen,  phosphorus,  potas- 
sium, and  calcium.  The  potato  through  its  life  re- 
quires liberal  supplies  of  the  first  three  of  these  elements, 
and  its  behavior  in  regard  to  these  is  similar  to  that  of 

30 


MANURING    AND    FERTILIZING  3 1 

a  shallow- rooted  root  crop.  The  fadls  that  the  potato 
is  a  starch-producing  crop,  and  that  its  period  of 
growth  is  through  the  summer  and  extending  well  into 
autumn  must  be  remembered.  In  these  features  it  is 
similar  to  corn,  but  distin(5lly  different  from  the  cereals 
which  ripen  in  the  summer,  as  it  is  assumed  that  it  is 
able  to  utilize  the  nitrates  and  other  plant-food  liber- 
ated during  the  summer  and  fall.  E.  Heckc'  states 
that  the  demand  for  nitrogen  is  especially  strong  dur- 
ing the  first  half  of  the  vegetative  period,  while  the 
demand  for  potash  is  greatest  during  the  second  half 
of  the  growing  period,  and  that  potash  aids  in  the  for- 
mation of  starch,  and  especially  in  the  development  of 
tubers  and  roots,  although  the  effedts  were  observed  in 
all  parts  of  the  plant. 

The  Influence  of  Nitrogen. — Wilfarth'  showed 
that  when  the  supply  of  nitrogen  is  insufficient  the 
leaves  tend  to  turn  yellow,  and  that  if  the  available 
supply  of  potash  is  deficient  heavy  applications  of  nitro- 
gen tend  to  reduce  the  percentage  of  tubers  and  starch. 
Lawes  and  Gilbert^  show  that  nitrogen  stimulates  the 
produ(5lion  of  starch,  provided  the  mineral  constituents 
are  not  deficient;  but  in  large  quantities  nitrogenous 
fertilizers  stimulated  luxuriant  growth,  delayed  matur- 
ation, and  produced  potatoes  richer  in  nitrogen  and 
much  more  liable  to  disease.  At  the  Rhode  Island 
Experiment  Station^  dried  blood  ranked  first  of  the 
nitrogenous  fertilizers  applied,  followed  by  nitrate  of 
soda  and  sulphate  of  ammonia;  but  on  soils  said  to  be 
extremely  acid,   dried  blood   was  only   about  half  as 


1  E.  S.  R.,  VII.,  p.  667.  2  E.  S.  R.    XIV.,  p.  561. 

=•  Rothamsted  Memoirs.  Vol.  VI.  *  R.  I.  Bui.  65,  pp.  133.  134. 


32  THE    POTATO 

beneficial  as  it  should  be;  hence,  such  soils  need  liming 
before  full  benefit  can  be  derived  from  the  use  of  this 
fertilizer.  A  mixture  of  two-thirds  dried  blood  and 
one-third  nitrate  of  soda,  or  of  equal  parts  of  all  three 
fertilizers,  is  suggested.  At  the  Tennessee  Experiment 
Station'  cottonseed-meal  was  found  to  be  a  more  profit- 
able source  of  nitrogen  than  nitrate  of  soda,  while  at 
the  Florida  Station"  the  nitrogen  of  cottonseed-meal 
and  castor  pomace  were  equally  effe(5live,  but  that  of 
nitrate  of  soda  was  more  so  b}'  30  per  cent. 

The  Influence  of  Potash. — Wilfarth  and  Wlm- 
mer  ^  show  that  when  pota.ssic  fertilizers  are  applied  to 
a  soil  almost  destitute  in  potash  they — 

1.  Increase  the  size  of  the  tuber,  but  have  little  influ- 

ence upon  its  composition,  and  that  the  amount 
of  potash  in  tubers  remains  fairly  constant,  unin- 
fluenced b}-  the  amounts  in  the  soil,  or  applied, 
unless  very  heavy  applications  are  made,  which 
may  cause  an  increase  to  a  certain  point,  but  will 
be  attended  by  a  decline  if  continued. 

2.  Decrease  the  percentage  of  stems  and  leaves,  but 

have  no  marked  influence  on  the  roots  of  potatoes. 

3.  Have  a  marked  influence  on  the  shape  and  appear- 

ance of  the  leaf;  if  deficient,  the  leaves  are  j^ellow- 
ish-brown  in  color,  and  become  spotted  or  striped 
in  the  portions  between  the  veins,  while  the  peti- 
ole of  the  leaf  and  ribs  retain  their  dark  green 
color.  If  the  supply  of  potash  is  insufficient  the 
leaves  tend  to  curl,  and  sometimes  collapse  of  the 
plant  follows. 

'  Tenn.  Bui.,  Vol.  XIII.,  No.  3,  p.  6.  ^  Fla.  Report,  1900-1901,  p.  27. 

'  E.  S.  R.,  XIV.,  p.  561. 


MANURING    AND    FERTILIZING  33 

4.  Increase  the  quantity  of  water  transpired  per  gram 
of  dry  matter. 

Hecke'  shows  that  the  appUcation  of  potassic  fertil- 
izers has  a  marked  influence  in  the  producftion  of 
tubers  and  roots,  and  that  potash  assists  in  the  forma- 
tion of  starch.  Lawes  and  Gilbert'  noted  that  the 
percentage  of  potash  was  relatively  high  when  the 
supply  of  it  was  relatively  liberal  and  vice  versa,  but 
the  variations  are  small,  and  that  where  there  was  a 
deficiency  of  potash  in  the  supply  and  in  the  ash  there 
was  generally  an  increased  supply  of  lime  in  the  ash. 

Which  is  the  Better  Source  of  Potash,  Sul- 
phate or  Muriate  of  Potash  ? — This  question  is 
still  unsettled,  because,  apart  from  other  considerations, 
one  of  the  deciding  fa(5lors  is  the  relative  cost  of  each. 
In  many  cases  the  results  are  inconclusive,'  while  in 
some  cases^  the  fertilizers  appear  to  be  of  equal  value. 
In  others"  sulphate  of  potash  gave  better  results;  thus 
Davidson,  of  Virginia,"  found  that  the  potatoes  grown 
by  sulphate  of  potash  contained  more  dry  matter  but 
a  less  percentage  of  starch  than  those  fertilized  with 
muriate  of  potash.  Brooks'  found  that  sulphate  of 
potash  gave  a  greater  yield  per  acre  of  merchantable 
tubers,  which  were  of  larger  size  and  of  superior  eat- 
ing quality,  containing  2  to  3  per  cent,  more  starch, 
and,  when  cooked,  the  potatoes  were  whiter,  of  better 
flavor,  and  more  mealv. 


'  E.  S.  R.,  VII.,  p.  667.  "-  Rothamsted    Memoirs,    Vol.   VI.,    "Experi- 

ments on  the  Growth  of  Potatoes."  ^  (N.Y.)  Geneva  Bui.  137,  pp.  604,  620. 
*  N.  H.  Bui.  41,  p.  13.  s  Mass.  (Hatch)  Report,  1S96,  p.  22  ;  R.  I.  Bui.  65, 
p.  133  ;  Mich.  Bui.  131,  p.  10;  (N.  Y.)  Geneva,  Bui.  137,  pp.  621,  622.  «  Va.  Bui. 
92,  pp.  107,  108.      '  Mass.  (Hatch)  Report,  1904,  p.  122. 


34  THE   POTATO 

The  time  and  method  of  application  must  be  con- 
sidered. In  my  experience  muriate  of  potash  has  given 
better  results  when  applied  the  previous  fall,  especially 
if  more  than  loo  pounds  per  acre  are  to  be  applied,  the 
presumption  being  that  the  potassium  compound  under- 
goes changes  in  the  soil,  and  that  the  injurious  chlorine 
is  removed  as  a  chloride  by  the  winter  and  spring 
rains.  For  spring  application  in  the  drills  sulphate  of 
potash  may  be  better,  or  a  mixture  of  sulphate  and  mu- 
riate of  potash,  if  more  than  the  above-mentioned 
quantity  is  required.  The  disadvantage  of  the  muriate 
of  potash  seems  to  be  due  to  the  fact  that  it  is  a  chlo- 
ride, and  Sjollema'  and  Pfeiffer^  have  shown  that  the 
chlorides  of  potassium,  sodium  (common  salt) ,  and  mag- 
nesium, when  added  to  the  sulphate  of  potash,  dimin- 
ished the  starch  content  of  the  potatoes  considerably, 
and  that  the  reduction  was  greatest  in  varieties  rich 
in  starch.  This  would  seem  to  support  the  common 
idea  that  sulphate  of  potash  produces  better  quality 
potatoes  than  muriate  of  potash.  Wheeler,'  of  Rhode 
Island,  shows  that  calcium  chloride  had  a  marked 
poisonous  effect  upon  potatoes  and  nearly  destroyed 
them,  while  the  same  amount  of  calcium  in  certain 
forms  other  than  the  chloride  or  sulphate  increased  the 
yield  and  vigor  of  the  plants.  New  varieties,  and 
those  making  a  heavy  growth  of  haulm,  seem  to  be 
particularly  sensitive  to  chlorides. 

Influence  of  Phosphoric  Acid.— Lack  of  phos- 
phoric acid  is  accompanied  by  dark  green  leaves.  While 
phosphoric  acid  aids  starch  formation,  it  is  often  re- 


1  E.  S.  R.,  XII.,  434.     »  E.  S.  R.,  XII.,  443-     '  H.  I.  Bui.  40,  PP.  85, 


MANURING    AND    FERTILIZING  35 

garded  as  being  of  less  importance  than  pofeash.  The 
results  obtained  at  the  Ohio  Station  '  show  that  phos- 
phoric acid  is  the  most  essential  fertilizer  for  their  con- 
ditions, some  potash,  and,  in  some  cases,  nitrogen,  being 
also  required.  I  found  the  same  to  be  true  at  Briar- 
cliff  Manor,  N.  Y.,  where  loo  pounds  of  available 
phosphoric  acid  per  acre  (equal  to  600  pounds  acid 
phosphate,  16-17  V^^  cent,  available)  gave  profitable 
returns.  My  own  observations  are  that  an  excessive 
application  of  available  phosphoric  acid  has  a  marked 
influence  upon  the  foliage,  causing  it  to  be  small,  dark 
green,  wrinkled,  and  apparently  stunted  in  develop- 
ment, with  consequently  early  maturity.  In  some 
cases  the  period  of  growth  is  reduced  six  or  eight 
weeks,  and  consequently  the  yield  is  low;  but,  owing 
to  the  potatoes  being  mature,  the  quality  is  generally 
good.  In  certain  localities,  for  early  potatoes,  where 
it  is  desirable  to  hasten  maturity,  the  use  of  fair  quan- 
tities of  acid  phosphate,  with  a  limited  supply  of  nitro- 
gen and  potash  and  no  barn  manure,  is  found  to  be 
good  pradlice.  The  nitrogen  may  be  supplied  in  an 
available  form  as  nitrate  of  soda,  since  nitrification 
may  not  be  adlive  in  the  soil  during  the  early  period 
of  growth. 

The  Influence  of  Calcium. — Calcium  does  not  343- 
pear  to  be  so  important  as  some  of  the  other  elements, 
although  in  some  cases  it  produces  a  marked  increase 
in  yield  (Fig.  10).  If  applied  in  a  form  which  has 
an  alkaline  acflion  upon  the  soil — as,  carbonate  of 
lime  or  quicklime — it  may  have  an  injurious  effedl  by 


'Ohio  Bui.  125,  pp.  131,  132. 


36  THE   POTATO 

producing  conditions  which  aid   the   development  of 
scab. 

Barn  Manure. — Applying  barn  manures  is  com- 
monly pradliced  for  potatoes  with  profitable  results. 
Lawes  and  Gilbert '  showed  that  only  a  small  portion 
of  the  nitrogen  of  farm  manures  is  taken  up  by  the  crop; 
thus,  with  an  annual  manuring  of  15.5  tons  per  acre, 
containing  200  pounds  of  nitrogen,  continued  for  twelve 


Courtesy  R.  I.  Exp.  SU.     See  Bui.  40. 

FIG.    lO — INFLUENCE    OF    LIME    UPON    POTATOES 
Showing  the  influence  of  lime  upon  the  yield,  and  that  it  increases  the  per- 
centage of  scabbed  potatoes.    Righl,  unlimed.    Left,  limed.    Other  fertil- 
izers the  same  in  both  cases. 

years,  but  8.3  per  cent,  of  the  nitrogen  was  recovered 
in  the  crop.  ' '  These  results  seem  to  indicate  that  this 
crop  is  able  to  avail  itself  of  a  less  proportion  of  the 
nitrogen  of  the  manure  than  any  other  farm  crop. 
Yet,  in  ordinary  pradlice,  farm-yard  manure  is  not  only 
largely  relied  upon  for  potatoes,  but  is  often  applied  in 
larger  quantities  for  them  than  for  any  other  crop." 
Taft,"  of  Michigan,  found  that  twenty-four  loads  of 
manure  per  acre  gave  the  largest  yield,  while  at  the 


'  Rothamsted  Memoirs,  Vol.  VI.       -  Mich.  Bui.  131,  p.  10. 


MANURING  AND   FERTILIZING  37  ^ 

Wisconsin  Experiment  Station  twentj'-  loads  per  acre 
were  applied,  and  larger  quantities  in  Great  Britan. 

It  seems  natural  to  assume  that  the  beneficial  effedts 
of  manure  must  largely  be  due  to  other  causes  than 
the  addition  of  plant- food.  Among  these  may  be  its 
influence  on  the  physical  properties  of  the  soil,  render- 
ing it  more  retentive  of  moisture,  more  porous  and 
more  permeable  for  air  and  roots,  and  a  better  home 
for  the  useful  soil  bacSleria,  which,  in  fact,  it  may  sup- 
ply. The  decomposition  of  such  quantities  of  organic 
matter,  with  the  consequent  liberation  of  carbon  dioxid, 
aids  in  rendering  the  mineral  resources  of  the  soil  more 
available.  Generally  speaking,  it  is  more  economical 
to  apply  about  ten  tons  of  manure  per  acre  and  supple- 
ment it  with  fertilizers,  except  upon  loose  open  soils 
of  poor  texture,  where  the  beneficial  effedl  from  the 
larger  amount  should  probably  be  ascribed  to  its  in- 
fluence upon  the  retention  of  moisture.  It  is  preferable 
that  the  manure  be  rotted  somewhat  and  applied  the 
previous  fall,  while  the  fertilizers  may  be  applied  when 
planting.  On  some  soils,  to  reduce  the  danger  of  dis- 
ease, it  may  be  advisable  to  apply  all  the  barn  manure 
to  the  previous  crop.  The  application  of  fertilizers  is 
profitable  under  most  conditions  in  the  Eastern  and 
North  Central  States.  At  New  Hampshire  Experi- 
ment Station  the  application  of  fifteen  cords  of  manure 
increased  the  yield  of  marketable  potatoes  over  loo 
bushels  per  acre  compared  with  no  manure,  and  the 
use  of  1 ,  500  pounds  of  fertilizers  with  the  same  amount 
of  manure  resulted  in  a  further  increase  in  yield  of 
130  bushels  per  acre.'     Taft,^  of  Michigan,  shows  that 

1  N.  H.  Bui.  Ill,  p.  ii6.       2  Mich.  Bui.  131,  p.  10. 


38  THE   POTATO 

the  average  gain  from  the  use  of  a  full  application 
of  fertilizers  was  eighty  bushels  per  acre.  In  Long 
Island,  N.  Y.,  a  fertilizer  mixture  containing  4  per 
cent,  nitrogen,  8  per  cent,  available  phosphoric  acid, 
and  10  per  cent,  potash  has  proven  satisfacftory.  It 
is  used  in  amounts  var3-ing  from  500  pounds  to  2,000 
pounds  per  acre,  and  in  many  cases  more  potash  is  ap- 
plied than  is  profitable.  The  use  of  1,000  pounds  of 
this  fertilizer  has  given  the  greatest  profit.  Where 
1 ,500  pounds  or  2,000  pounds  were  used  the  cost  of  the 
fertilizer  w^as  more  than  the  market  value  of  the  in- 
creased yield  of  potatoes.  For  some  years  I  have  used  a 
mixture  of  100  pounds  sulphate  of  ammonia,  400  to  600 
pounds  acid  phosphate  (16  to  17  per  cent,  available), 
and  100  pounds  muriate  of  potash  with  eight  to  ten 
tons  of  partially  rotted  manure  per  acre  on  a  medium 
loam  soil.  At  New  Hampshire  Experiment  Station' 
300  pounds  muriate  of  potash  per  acre  gave  the  best 
results  when  compared  with  none,  150  pounds,  and  450 
pounds  per  acre. 

The  above  mixtures  merely  show  quantities  used  by 
certain  individuals  ;  each  farmer  must  work  out  a  mix- 
ture suited  to  his  needs.  There  are  other  conditions 
than  the  application  of  fertilizers.  As  Dr.  W.  H.  Jordan' 
pithily  puts  it :  "It  is  clearl)^  evident  that  a  large 
supply  of  plant-food  does  not  necessarily  insure  a 
satisfactory  crop.  Other  conditions  which  largely  per- 
tain to  culture — such  as  texture,  humus,  and  water- 
supply — exercise  a  controlling  influence,  and  when 
these  conditions  are  unfavorable  their  effedt  is  not  over- 
come by  heavy  applications  of  fertilizer. ' ' 

'  N.  H.  Bui.  Ill,  p.  115.       2(N.  Y.)  Geneva  Bui.  187,  p.  215. 


MANURING    AND    FERTILIZING  39 

It  almost  invariably  occurs  that  potatoes  grown  with- 
out any  manure  mature  earlier  and  contain  more  dry 
matter,  with  a  correspondingly  reduced  yield,'  than 
those  grown  on  land  manured  with  barn  manures  or 
a  complete  fertilizer.  The  vigorous  growth  induced 
under  the  latter  conditions  cannot  be  matured  in  the 
same  time,  hence  for  an  early  crop  it  is  unwise  to 
stimulate  too  vigorous  growth. 

The  Function  of  Fertilizers. — The  prevaihng 
opinion  in  purchasing  fertilizers  is  that  they  contain 
a  certain  amount  of  plant-food — usually  nitrogen,  phos- 
phoric acid,  or  potash — in  a  more  or  less  available 
form,  and  that  the  benefits  received  from  their  appli- 
cation is  due  to  the  addition  of  this  plant-food  to  the 
soil.  So  deeply  seated  is  this  theory  that  all  fertilizers 
are  bought  and  sold  on  this  basis,  and  laws  controlling 
the  business  have  been  formulated  upon  it.  The  in- 
gredients— nitrogen,  phosphoric  acid,  and  potash,  wath 
others — are  necessary  for  the  growth  of  all  crops,  but 
the  amounts  of  the  essential  ingredients,  other  than 
the  above  mentioned,  are  believed  to  be  present  in  the 
soil  in  sufficient  quantities  to  meet  all  the  requirements 
of  the  crops  grown. 

A  300-bushel  crop  of  potatoes  has  been  found  to  con- 
tain 81  pounds  of  nitrogen,  30.6  pounds  of  phosphoric 
acid,  and  79  pounds  of  potash.  Taking  49  New  York 
soils,  the  chemist  found  that  the  surface  eight  inches 
contained,  per  acre  : " 

Nitrogen    .     .     .     3,053  pounds,  enough  for    3S  crops 
Phosphoric    acid,    4,219         "  "         "     137     " 

Potash  ....    16,317         "  "         "    207     " 


1  Va.  Bui.  92,  p.  107.  2  (N.  Y.)  Cornell  Bui.  130,  p.  157. 


40  THE   POTATO 

Upon  such  soils  as  these  applications  of  fertilizers 
containing  phosphoric  acid,  and,  in  some  cases,  potash, 
have  been  found,  by  experience,  to  be  most  profitable — 
a  condition  of  affairs  which  could  never  be  ascertained 
from  the  analyses.  It  is  seldom  that  the  increase  in 
yield  of  crop  bears  any  relationship  to  the  quantity  of 
the  fertilizers  applied.  Without  either  fertilizers  or 
manure,  but  given  good  tillage.  3'ields  of  300  bushels 
of  potatoes  per  acre  have  been  obtained  for  four  suc- 
cessive years  on  the  same  piece  of  land.' 

The  amount  of  plant-food  removed  by  any  crop  is 
small,  and  is  obtained  from  all  parts  of  the  soil  wherever 
roots  extend.  Most  soils  contain  certain  sufficient  plant- 
food  to  supply  the  demands  of  any  crop  grown  thereon 
for  an  indefinite  period  of  time.  To  maintain  crop  pro- 
du(5lion  at  a  profitable  point,  attention  must  be  paid 
to  fadtors  other  than  the  supply  of  plant-food. 

The  ingredients  applied  as  fertilizers  will,  no  doubt, 
be  found  to  have  a  value  other  than  their  value  as  car- 
riers of  plant-food.  Their  value  for  this  purpose  may 
be  found  to  be  small,  while  the  benefits  derived  from 
their  use  may  be  found  to  be  largely  due  to  their 
chemical  adlion  upon  the  soil — e.g. ,  as  sanitary  agents, 
promoters  of  the  growth  of  desirable  organisms  or  de- 
stroyers of  injurious  ones,  aids  in  the  formation  of  de- 
sirable chemical  compounds  in  the  soil  or  neutralizers 
of  undesirable  compounds,  to  their  influence  as  stimu- 
lants, and  upon  the  physical  properties  of  the  soil. 
That  their  use  is  desirable  in  some  cases  is  evident. 
Why  it  should  be,  and  how,  are  matters  for  investiga- 
tion. 

1  (N.  Y.)  Cornell  Bui.  191,  p.  192. 


MANURING    AND    FKRTIIJZING  41 

The  farmer  needs  to  realize  that  the  soil  on  his  fields 
to-day  is  not  the  same  as  that  of  last  3-ear.  Soil  is 
changing.  The  subsoil  of  yesterday  is  the  soil  of 
to-day.  Although  the  amount  removed  b)-  crops  is  so 
small  that  it  is  a  negligable  quantity,  that  removed  by 
washing  and  by  the  wind  is  enormous.  The  mudd)^ 
stream,  the  bars  at  the  mouths  of  rivers,  the  move- 
ment of  soils  by  the  wind,  and  even  the  dust-cloud 
raised  when  harrowing,  show  that  far  more  plant-food 
is  removed  in  these  waj-s  than  in  crops,  and  to  check 
these  leaks  is  of  more  importance  than  to  try  to  make 
up  the  loss  by  the  addition  of  plant-food.  The  main- 
tenance of  a  satisfadlory  amount  of  organic  matter  in 
the  soil  in  a  proper  condition  maj^  usually  be  accom- 
plished by  a  judicious  rotation  of  crops,  manuring,  and 
liming. 

' '  The  old  method  has  been  to  feed  crops  with  com- 
mercial fertilizers,  the  new  agriculture  looks  to  nature 
for  its  sources  of  plant-food.  These  sources  are  (i) 
the  large  stores  of  unavailable  plant-food  in  all  soils, 
(2)  the  unlimited  stores  of  nitrogen  present  in  the 
air.'"  Research  has  revealed  the  facft  that  soil  or- 
ganisms can  take  plant-food  from  both  of  the  above 
sources  and  furnish  it  to  growing  crops,  and  that  a 
fertile  soil  is  one  in  which  these  processes  are  going  on 
at  the  highest  rate,  and  that  it  is  necessary  to  stimu- 
late these  biological  activities.  Humus  is  a  food  for 
these  organisms.  Lime  is  essential  for  maintaining  the 
soil  in  a  slightly  alkaline  condition,  and  for  fixing 
some  of  the  compounds  formed  in  the  soil;  and  drain- 


'  Del.  Bui.  66,  p.  14. 


42  THE   POTATO 

age,  deep  plowing,  and  thorough  tillage  are  necessary 
to  bring  air  into  the  soil  and  stimulate  badlerial  adtiv- 
it}'.  Humus,  lime,  and  tillage  are  three  important  fac- 
tors in  maintaining  a  fertile  soil,'  and  the  farmer  who 
understands  the  value  of  these  is  the  one  who  will  de- 
rive the  most  benefit  from  the  use  of  fertilizers. 

Purchasing  and   Applying  Fertilizers. — Fertil- 
izers may  be  divided  into  three  classes — viz. : 
(a)  Nitrogenous,  or  those  rich  in  nitrogen. 
(d)    Phosphatic,  or  those  rich  in  phosphorus. 
(c)    Potassic,  or  those  rich  in  potassium. 
Nitrogen  occurs  in  fertilizers,  as  : 

(i)  Nitrates — e.g.,    nitrate   of    soda,    nitrate    of 
potash. 

(2)  Ammonium    salts  —  f-g-,  sulphate    of    am- 

monia. 

(3)  Organic  nitrogen — e.g.,  dried  blood,  tankage, 

hoof  meal,  etc. 

Nitrogen  as  nitrates  is  immediately  available 
as  plant-food,  is  soluble  in  water,  and  if 
not  taken  up  quickly  by  plants  is  liable 
to  be  lost  in  the  soil  water;  hence  small 
quantities  applied  at  short  interv^als  give  the 
best  results. 

Nitrogen  as  ammonium  salts  soon  becomes 
available  in  warm  weather,  and  is  not  so 
liable  to  be  washed  out  of  the  soil  as  when  in 
the  form  of  a  nitrate. 

Nitrogen  as  organic  matter  is  more  slowly 
available. 


1  Del.  Bui.  66,  "  Soil  Bacteria  and  Nitrogen  Assimilation. 


MANURING    AND    FKKTILIZING  43 

Phosphorus  occurs  in  fertihzers,  as  : 

( 1 )  Insoluble  phosphate  of  lime — e.g. ,  floats,  bone 

meal,  tankage. 

(2)  Soluble  phosphate  of  lime — e.g.,   acid  phos- 

phate, dissolved  bone. 
Insoluble  phosphate  of  lime  is  considered  to 
be  but  slowly  available.     It  is  converted 
into  "  soluble  "  by  treating  it  with  an  acid, 
usually  sulphuric  acid. 
Soluble  phosphate  of  lime,  as  a  rule,  is  more 
active    than   insoluble  in  promoting  plant 
growth,   but  on  acid  soils  insoluble  phos- 
phate   often   gives   better   returns.       The 
soluble  phosphate  of  lime  and  a  phosphate 
soluble  in  weak  acids  constitute  the  ' '  avail- 
able phosphoric  acid  ' '  of  the  chemist. 
Pota.ssium  is  the  valuable  ingredient  found  in  : 

Wood  ashes,  kainit,  sulphate  of  potash,  double 

salts,  and  muriate  of  potash. 
It  usually  gives  good  returns  when  applied  to 
light,   sandy,   and  peaty  soils.      As- kainit 
contains  chlorides  and  muriate  of  potash  is 
a  chloride,   it  is  often  advisable  to  apply 
them  some  time  previous  to   planting  the 
crop,  in  order  that  the  injurious  substances 
may  be  removed  by  the  soil  water,  chlorides, 
in  excess,  being  injurious  to  potatoes. 
Value. — All  fertilizers  may  be  valued  according  to 
the  percentage  of  nitrogen,  soluble  phosphate  of  lime, 
insoluble  phosphate  of  lime,  and  potash  present.    They 
are  often  valued  on  the  unit  system.     A  unit  is  one  per 
cent,  of  a  ton,  or  20  pounds;  the  ton,  2,000  pounds. 


44  THE    POTATO 

Unit  Value. — In  order  to  find  the  unit  value  of  the 
different  ingredients,  divide  the  price  per  ton  of  the 
fertiHzer  by  the  percentage,  or  number,  of  units  of  the 
various  vakiable  ingredients;  this  will  give  the  cost  per 
unit.  For  example,  if  sulphate  of  ammonia  be  $66.00 
per  ton  and  contains  20  per  cent,  of  nitrogen,  then 
66  ^  20  =  3.30  per  unit  (see  Table,  p.  45). 

If  the  price  per  pound  be  desired,  divide  the  price 
per  unit  by  20,  or  the  number  of  pounds  in  the  unit; 
thus,  3.30  H-  20  =  16.5  cents  per  pound. 

For  a  fertilizer  containing  several  ingredients,  find 
the  lowest  cost  of  each  ingredient  in  a  standard  fertil- 
izer-— as,  nitrate  of  soda  for  nitrogen,  muriate  of  potash 
for  potash,  and  acid  phosphate  for  .soluble  phosphoric 
acid — and  compare  it  with  these. 

Purchasing  Fertilizers. — In  purchasing  fertilizers 
it  is  advisable  to  write  for  quotations  with  guaranteed 
analyses,  ascertain,  as  indicated  above,  the  cheapest 
source  of  the  valuable  ingredients,  and  then  purchase. 

The  fertilizer  containing  a  unit  of  plant-food  at  the 
lowest  cost  is  generally  the  one  to  buy.  In  figuring 
the  cost  always  include  the  freight,  cost  of  hauling, 
and  handling;  for  instance,  one  ton  of  muriate  of  pot- 
ash contains  as  much  potash  as  four  tons  of  kainit, 
hence  the  potash  as  muriate  of  potash  costs  only  one- 
quarter  as  much  for  haulage  and  handling.  The  same 
applies  to  high  grade  acid  phosphate  and  low  grade, 
and  unless  the  filler  is  of  some  particular  value  it  is 
wise  to  take  the  high  grade  or  concentrated  goods. 

Barn  Manure. — When  not  applied  to  the  fields 
as  soon  as  made,  it  should  be  stored  under  cover  and 
the   excrete    from   the  various  farm  animals  mixed, 


MANURING   AND    FERTILIZING 


45 


TABLE    III 


SHOWING  THE     COST    OF    THE    DIFFERENT    INGREDIENTS    IN 
CERTAIN  FERTILIZERS  DURING  1904 


VALUABLE   INGREDIENTS 

COST 

NAME   OF    FERTILIZER 

Percentage 

of  Insoluble 

Phosphoric  Acid 

•SS 

1^ 

Per 
Ton 

Per 
Unit 

Per 

Lb. 

Nitrate  of  Soda  .... 

15-5 
20 

13 

4 

$ 
44.00 
66.00 

45.00 
3H.00 
28.00 

26.00 

27.00 

34-00 

11.00 
15  00 
40.00 
12.00 

26.00 
48.00 
43.00 

1. 10 
1.24 

$ 
2.84 
3-30 

3-46 

2.84 

.76 

2.84 

.80 

2.S4 

•91 
2.84 

1.57 
•85 
•94 
1. 00 
1. 00 

I  00 
1.00 

Cis. 
14.2 

Sulphate  of  Ammonia  . 
Dried  Blood   (high 

grade) 

Dried  Blood 

16.5 

16.9 
14.2 
3-8 
14.2 

Fresh  Bone   Meal  .    .    ] 

22 

1-25 

■    1 

28 

40 
14.2 

Fine  Ground  Bone      j 

5 

Tankage i 

14 

4-5 
14.2 

, 

7 

Fine    Ground   Bone    '  ' 

Tankage ( 

9 

78 

Acid   Phosphate  .... 
Acid    Phosphate  .... 
Acid   Phosphate  .... 

13 
16 
40 

4.2 

4  7 

^•o 

12 

26 
48 
50 

5.0 

Double  Salts  of  Potash 

5.0 

Sulphate  of  Potash.  .    . 

50 

4.3 

I 
I 

86 
42 
38 
43 
42 
38 
43 

Analysis  of  a  ton   of  I 

■45 

7.1 

•  54 

"  .61' 

1-9 

2.1 

•63 

7.1 

Another  sample  of        1 
Manure j 

.14 

'  '.67' 

1^9 
2.1 

when  the  cokl  cow  and  pig  manure  will  tend  to  pre- 
vent excessive  loss,  by  heating,  from  the  horse  ma- 
nure. Young  growing  animals  and  those  bearing 
young  and  giving  milk  will  give  poorer  excrete  than 


46  THE   POTATO 

mature  fattening  animals.     The  food  and   the   litter 
used  also  affect  the  value  of  the  manure. 

In  barn  manure  the  nitrogen,  phosphoric  acid  and 
potash  are  slowly  available,  and  are  arbitrarily  reck- 
oned to  be  worth  half  what  they  would  cost  in  fer- 
tilizers. The  value  of  a  ton  of  manure  for  its  physical 
effect  upon  soils  cannot  be  expressed  in  dollars  and 
cents,  but  in  the  Eastern  States  it  may  be  presumed  to 
vary  between  50  cents  and  $1.00  per  ton;  for  while  the 
fertilizing  ingredients  show  a  value  of  about  $1.25, 
the  manure  often  costs,  or  is  valued  at,  $2.00  per  ton. 

Mixing  Fertilizers. — Fertilizer  manufacturers  lay 
great  emphasis  on  the  value  of  proper  mixing,  and 
usually  charge  from  $5  to  $10  per  ton  for  doing  it. 
For  example,  a  commercial  potato  manure  analyzing 
nitrogen,  3  percent.,  phosphoric  acid,  6  per  cent.,  and 
potash,  ID  per  cent,  costs  in  New  Hampshire',  in  1904, 
$36.50  per  ton.  A  fertilizer  made  up  by  the  station 
on  the  same  formula  was  just  as  satisfadlory,  and 
after  allowing  $1.00  per  ton  for  mixing,  it  cost  $24 
per  ton,  a  saving  of  $8.50  per  ton,  or  using  1,500 
pounds  per  acre  =:  $7.10  per  acre. 

To  compound  this  fertilizer: 
3  per  cent,  nitrogen  =  60  pounds  nitrogen  in  a  ton 

(2,000  pounds). 
6  per  cent,  phosphoric  acid  =  120  pounds  phosphoric 

acid  in  a  ton. 
10  per  cent,  potash  =  200  pounds  potash  in  a  ton. 

Nitrate  of  soda  will  furnish  nitrogen  for  immediate 
use,  and  the  nitrogen  of  the  sulphate  of  ammonia  will 


1  N.  H.  Bui.  III.,  p.  no. 


MANURING   AND   FERTILIZING  47 

become  available  later  on,  hence  we  may  take  23^ 
pounds  nitrogen  in  the  form  of  nitrate  of  soda,  and 
36^  pounds  in  the  form  of  sulphate  of  ammonia. 
Cottonseed-meal,  dried  blood,  tankage,  etc.,  might 
also  be  used  if  desired. 

Pounds 

Nitrate  of  soda  containing  151^^  percent,  nitrogen;  to  fur- 
nish 23I4  pounds  nitrogen  it  requires  150  pounds      .        150 

Sulphate  of  ammonia  containing  20  per  cent,  nitrogen; 
to  furnish  36%  pounds  nitrogen,  it  requires  1S4 
pounds 1S4 

Acid  phosphate  containing  16  per  cent,  available  phos- 
phoric acid;  to  furnish  120  pounds  phosphoric  acid  it 
requires  750  pounds 750 

Muriate  of   Potash  containing   50  per  cent,   potash;  to 

furnish  200  pounds  potash  it  requires  400  pounds     .       400 

Filling,  sand,  etc.,  used  to  make  weight  if  desired     .     .       516 


2,000 


Unless  care  be  taken  in  mixing  fertilizers  loss  of 
valuable  ingredients  may  result. 

1 .  Nitrate  of  soda  and  soluble  phosphate  of  lime — as, 

acid  phosphate — must  not  be  mixed  and  allowed 
to  stand  for  any  length  of  time,  or  chemical  adtion 
will  take  place,  resulting  in  a  loss  of  nitrogen  and 
phosphoric  acid. 

2.  Do  not  mix  an  ammonium  salt — as,  sulphate  of  am- 

monia— with  any  other  fertilizer  containing  free 
lime,  as  the  lime  will  set  free  the  ammonia,  which 
will  be  lost. 

3.  Do  not  mix  soluble  and  insoluble  phosphates  to- 

gether. 


48  THE   POTATO 

4.  Nitrate  of  soda   is  very  deliquescent,   and   if  left 

mixed  with  other  fertilizers  is  liable  to  render  the 
whole  mass  wet  and  pasty,  and  so  difficult  to 
apply.  Cottonseed-meal  is  a  very  useful  source 
for  part  of  the  nitrogen  of  mixtures.  If  it  is  nec- 
essary to  hold  a  quantity  of  nitrate  of  soda  for  a 
time,  it  is  advisable  to  empty  it  out  of  the  bags, 
as  they  are  liable  to  ignite  spontaneously.  When 
emptied  do  not  leave  the  bags  lying  in  a  heap  in 
the  corner  of  the  barn.  Store  nitrate  of  soda  in  a 
dry  place. 

5.  Kainit  is  also  very  deliquescent,  and  it  is  the  worst 

potassic  fertilizer  to  use  in  a  mixture  on  this  ac- 
count.    Sulphate  or  muriate  of  potash  are  better 
for  mixtures. 
Applying  Fertilizers. — When  a  horse  planter  is 
used  the  fertilizer  is  usuall}'  distributed  in  the  row  at 
the  time  of  planting.      The    fertilizer   may  be  sown 
broadcast  or  in  the  rows  as  desired,  but  it  should  be 
incorporated  with  the  soil  and  not  left  on  top. 

Water  Requirement. — It  has  been  shown  clearly 
that  the  available  water  content  of  the  soil  exerts  a 
great  influence  upon  the  life  of  the  potato  plant,  upon 
its  assimilation  of  plant-food,  and  upon  the  yield.  At 
the  Wisconsin  Experiment  Station '  it  was  found  that 
when  two  acre  inches  of  water  were  added  in  two  irri- 
gations in  one  case  the  yield  was  increased  100  bushels 
of  salable  potatoes  per  acre,  thus  showing  that  the 
right  amount  of  water  at  the  right  time  is  a  very  im- 
portant factor  in  determining  the  yield.     Whitson,'  of 


1  wis.  Report,  1899,  p.  213.  ^  Wis.  Report,  1902,  p.  190. 


MANURING   AND    FERTILIZING  49 

Wisconsin,  shows  that  if  it  is  assumed  that  under  the 
existing  cHmatic  conditions  of  that  State  1 8  inches  of 
rainfall  during  the  growing  season  is  sufficient  for  po- 
tatoes, then,  on  this  basis,  there  was  a  shortage  of  4 
inches  or  more  in  ten  of  the  past  twentj^-one  years.  In 
Utah '  it  was  noted  that  the  largest  yield  was  obtained 
from  a  plat  irrigated  every  eighth  day  and  receiving.  14 
inches  of  water,  and  another  year  ^  16.62  inches  of  water 
with  pra(5lically  no  rain  produced  a  yield  of  423  bushels 
per  acre.  The  importance  of  water  was  also  shown  at 
the  same  station,'  when  amounts  of  water  varying  be- 
tween 4.3  inches  and  9.45  inches  were  applied  between 
July  18  and  August  6,  and  the  yield  increased  with 
the  increase  in  amount  of  water.  At  the  New  Jersey 
Station^  irrigation  increased  the  yield  36.4  per  cent., 
while  at  Wisconsin  the  increase  has  been  159.58  ^  bush- 
els per  acre  over  the  unirrigated  plat,  and  the  average 
gain  per  year  during  the  six  years — 1 896-1901 — was 
83.9  bushels  per  acre.  That  some  risk  must  be  taken 
in  irrigating  heavy  soils  in  a  humid  climate  was 
demonstrated  at  Wisconsin."  Thus,  in  one  year, 
while  there  was  an  increase  of  81.4  bushels  per  acre 
from  irrigating  sandy  land,  on  heavier  land  the  yield 
was  reduced  56  bushels  per  acre  because  heavy  rain 
followed  the  second  irrigation. 

Corn  and  potatoes  require  somewhat  similar  amounts 
of  water  to  make  one  pound  of  dry  matter.  The  figures 
of  Wilfarth  and  Wimmer '  and  Whitson*  are  as  follows: 


'  Utah  Report,  1893,  p.  180.  2  utah  Bui.  26,  p.  14. 

'  Utah  Bui.  5.  *  N.  J.  Report,  1900,  p.  184. 

^Wis.  Report,  1901,  p.  19S.  «  Wis.  Report,  1900,  p.  188. 

'  E.  S.  R.,  XIV..  p.  561.  "  Wis.  Report,  1902,  p.  191. 


50 


THE   POTATO 


WATER  USED   PER    POUND   OF  DRY   MATTER 


WILFARTH   AND   WIMMER 

Pounds 
Potatoes      .     .     .     200  to  230 
Tobacco       ,     .      .     300  to  370 

Buckwheat 400 

Chicory 400 

Mustard 500 

Oats 460 


WHITSON 

Pounds 

Corn 270 

Soy-beans 527 

Clover 576 

Oats 503 


King '  has  shown  that  the  amount  of  water  required 
to  make  one  pound  of  dry  matter  in  the  tuber  and  vine 
of  potatoes  varied  between  272  pounds  and  497  pounds 
during  the  years  1892-7,  while  that  for  oats  ranged  be- 
tween 446  and  595  pounds;  barley,  375  to  404  pounds; 
peas,  477;  corn,  223  to  398  pounds;  clover  (first crop), 
370  to  582  pounds;  clover  (second  crop),  730  to  983 
pounds. 


'  "Irrigation  and  Drainage."     F.  II.  King. 


CHAPTER  VI 
CONSIDERATIONS   OF    SEED 

Source  of  Seed. — It  is  often  advised  that  potatoes 
be  obtained  from  another  soil  and  from  a  more  north- 
ern latitude  if  vigor  and  delayed  maturity  are  desired, 
and  from  a  southern  latitude  if  earliness  is  sought; 
but,  generally  speaking,  potatoes  bred  for  a  distridl  do 
better  there  than  elsewhere.  Few  European  varieties 
of  potatoes  are  worth  growing  in  America,  and  any  in- 
trodu(5lion  requires  acclimatization  and  selecftion.  In 
England  we  noted  that  northern  grown  Scotch  seed 
did  not  yield  so  heavily  the  first  year  as  the  second, 
and  the  same  was  true  of  Maine  grown  seed  in  the 
Hudson  River  valley.  Brooks,'  of  Massachusetts, 
and  Bishop,  of  Maryland,  report  exac5lly  to  the  con- 
trary, although  in  a  subsequent  j-ear  Brinkley,^  at  the 
same  station,  obtained  higher  ^nelds  from  home  grown 
seed.  The  Rhode  Island  Station^  found  that  varieties 
which  produced  large  yields  gave  increasing  yields  the 
longer  the  seed  tubers  had  been  home  grown,  and  that 
those  which  produced  smaller  yields  gave  diminishing 
yields  the  longer  the  seed  had  been  home  grown.  At 
Louisiana  Station^  home  grown  seed  was  equal  to,  if 
not  better,  than  western,  or  eastern  grown  or  Boston 
seed.     At  Georgia  Station^  southern  grown  seed  did 


>  Mass.  (Hatch)  Report,  1896,  pp.  25,  26.      2  Md.  Bui.  17,  p.  257. 

3  R.  I.  Report,  1S97,  p.  380.  *  I,a.  Sacond  Series  Bui.  4,  p.  77. 

•Ga.  Bui.  17,  p.  166. 

51 


52  THE   POTATO 

best,  and  the  statement  is  made  that  the  value  of  seed 
depends  more  upon  the  care  exercised  in  the  seled:ion 
of  the  strain  than  the  locahty  where  it  is  grown. 
Martinet',  of  France,  reports  that  in  several  diversified 
trials  seed  tubers  from  higher  altitudes  gave  better 
yields  under  all  circumstances. 

Bailey-,  of  Cornell,  lodges  a  criticism  against  the 
comparison  of  northern  and  southern  grown  seed.  He 
believes  the  variations  to  be  due  much  more  to  the 
stock  itself — how  the  plants  have  been  grown  and 
handled  in  previous  years — than  to  any  influence  of 
latitude.  He  believes  it  to  be  impossible  to  secure 
stock  from  different  growers  which  is  sufficiently  uni- 
form to  allow  of  comparative  experimentation.  That 
such  variation  exists  is  shown  by  Brooks'^  obser\^ation 
on  Beauty  of  Hebron  and  Early  Rose  potatoes.  Seed 
potatoes  of  the  same  variety  obtained  from  different 
localities  gave  a  variation  in  yield  of  about  50  per  cent, 
for  each  variety.  Probably  the  matter  is  one  of  indi- 
viduality. It  is  necessary  to  study  each  potato  and 
hill,  and  perpetuate  a  variety  suited  to  the  particular 
environment.  If  this  variety  possesses  the  capacity''  of 
adapting  itself  rapidly  to  other  environments  it  is  more 
useful,  but  it  must  be  able  to  grow  vigorously  and 
mature  its  tubers  in  order  to  maintain  its  value.  The 
Ohio  Experiment  Station^  found  that  the  selection  and 
storage  of  potatoes  is  of  more  importance  than  the  use 
of  seed  grown  on  other  soil.  Kansas  Experiment  Sta- 
tion* found  that  tubers  matured  in  July  were  the  most 


1  E.  S.  R.,  XII.,  p.  636.  2  (N.  Y.)  Cornell  Bui.  25,  p.  175. 

'  Mass.  (Hatch)  Report  1899,  P-  ^2  ■*  Ohio  Bui.  76,  p.  46. 

*  Kans.  Bui.  37,  pp.  155,  136. 


CONSIDERATIONS   OF    SEED 


53 


satisfadlory  seed  for  the  second  crop,  and  the  pra(5lice 
of  using  first-crop  tubers  as  seed  for  the  second  crop 
is  rapidly  gaining  ground  in  the  South,  owing  to  the 
difficulty  of  holding  seed  over. 

Management  of  Potatoes  Previous  to  Plant- 
ing.— The  best  way  to  hold  seed  potatoes  is  in  cold 
storage  at  a  temperature  of  33°  to  35°  F.  Should  the 
temperature  fall  to  freezing-point  (32°  F.)  for  a  short 


2'   6 


FIG.    II — A    USEFUL    POTATO    TKAY    FOR    THE    STORAGE    AND 
SPROUTING   OF    SEED    POTATOES 

For  small  quantities,  a  useful  size  is  24  x  12  inches.    This  size  will  hold 

about  forty  pounds  of  tubers,  and  can  be  conveniently  handled.    The 

larger  size  holds  about  eighty  pounds  of  tubers. 

time  probably  no  harm  will  result,  as  the  freezing- 
point  of  potatoes  is  rather  lower  than  that  of  water. 
As  most  farmers  do  not  have  cold  storage  some  sub- 
stitute must  be  found.  A  cool,  fairly  dry  cellar,  or  a 
root-house,  is  a  very  good  alternative,  or,  failing  this, 
the  potatoes  may  be  pitted  outside  and  covered  so  that 
no  frost  can  reach  them  (see  "Storing").  Several 
weeks  before  planting  the  tubers  should  be  spread  out 
on  the  barn  floor  two  or  three  thick,  in  the  light,  to 
quicken  growth.     Potatoes  vary  in  the  time  they  take 


54  THE    POTATO 

to  germinate.  Mature  potatoes  will  not  begin  to  grow 
until  they  have  had  a  period  of  rest.  In  some  varie- 
ties this  may  be  but  a  few  weeks,  while  others  may 
be  held  months  before  they  show  signs  of  growth. 
In  the  island  of  Jersey  and  the  early  potato  grow- 
ing districts  of  the  United  Kingdom  it  is  customary 
to  store  the  seed  potatoes  in  flat  trays  (Fig.  ii). 
The  advantages  of  these  are:  (i)  the  seed  cannot  heat; 
(2)  a  large  quantity  can  be  stored  in  a  room,  the  trays 
being  tiered  almost  to  the  roof;  (3)  seed  can  be  easily 
examined  at  any  time  and  conveniently  moved,  hence 
diseases — as,  wet-rot,  dry-rot,  etc. — are  more  easily  con- 
trolled; (4)  the  potatoes  may  be  sprouted  in  the  traj^s; 
(5)  the  potatoes  can  be  moved  to  the  field  in  and 
planted  from  the  trays. 

The  tray  is  the  best  means  of  storing  new  varieties 
which  have  been  purchased  or  grown  in  small  quan- 
tities. 

Sprouting  Potatoes.— Lavallee'  and  many  others 
have  found  that  sprouting  seed  potatoes  in  a  well- 
lighted  room  increases  the  yield  and  earliness,  and 
produces  a  more  vigorous  growth  of  vines  and  a  larger 
starch  content  in  the  tubers.  One  explanation  offered 
for  the  increase  in  j'ield  is  that  the  short,  thick  stem 
developed  under  the  above  conditions  bears  many 
scales  or  leaves  for  its  hight,  and  it  is  from  the  axils 
of  these  scales,  the  place  where  the  scale  joins  the 
stem,  that  the  tuber-bearing  branches  are  produced 
(Fig.  12).  The  more  scales  produced,  the  more  op- 
portunity for  the  development  of  tubers.  If  the  tu- 
bers start  growth  in  the  dark,  either  indoors  or  below 

1  E.  S.  R.,  XII.,  p.  1032. 


CONSIDERATIONS    OF    SEED 


55 


ground,  the  scales  are  formed  at  longer  intervals,  and 
there  are  correspondingly  fewer  places  for  the  produc- 
tion of  tuber-bearing   branches.     Also,  in   the  latter 


FIG.  12 — POTATO  PLANTED  FOUR  INCHES  DEEP 
{DiagranDiiat  ic) 
a— Ground  level.  i5— Seed  potato,  c— Short  sprout  sent  up  before  plant- 
ing, which  sent  up  two  branches,  d,  e  \  d  being  broken  off,  and  e  cut  off  at/. 
^^— The  tuber-bearing  stem,  or  rhizome,  which  bears  buds  at  h,  and  thickens 
at  the  end  to  form  a  tuber,  /,  upon  which  eyes  having  buds,  k,  niaj'  be  seen 
m  is  a  tuber-bearing  branch,  or  rhizome,  which  has  not  yet  begun  to  form 
a  tuber,  and  r  shows  where  the  roots  were  broken  off.  Generally  four  roots 
are  sent  out  for  each  tuber-bearing  branch. 


case,  the  leaf-bearing  branches  produced  above  ground 
are  weaker.  The  system  is  considered  essential  in 
the  island  of  Jerse}-  and  the  early  potato  growing  dis- 
tricts of  the  United  Kingdom,  and  is  practiced  to  a 
small  extent  for  the  .second  crop  in  the  Southern  States. 


K^CS.  IS,   14,  1:> 


Cornell  Univ.  Dej)!.  of  Ilortii'iiltu 


FIG.   13 — POTATOES  SPROU'ED  PROPER    LENGTH    FOR    THE  PLANTER 
Starting  the  growth  of  the  tubers  in  this  way  is  profitable  in  many  places. 


K-IG.    14 — EARLY    POTATOES    SPROUTED    FOR    HAND    PLANTING 
lyOnger  sprouts  than  these  should  not  be  permitted  to  deve  lop. 


56 


CONSIDERATIONvS    OF    vSEED 


57 


By  sprouting  the  seed  tubers,  the  Kansas  Experiment 
Station'  have  planted  potatoes  in  March  and  Hfted  the 
crop  on  June  i.  At  the  Rhode  Island  Experiment  Sta- 
tion" potatoes  were  held  in  a  fairly  well-lighted  room 
at  a  temperature  of  60°  to  75°  F.  for  four  to  six  weeks. 


FIG.   15 — SPROUTS    TOO    LONG   AND    WEAK 

This  often  occurs  when  potatoes  are  left  in  sacks,  barrels,  or  in  piles  in  the 

cellar.     As  soon  as  sprouting  begins,  spread  the  tubers  thinly  on  the  barn 

floor,  in  the  light,  to  check  this  waste  of  energy. 


In  this  time  thick  buds,  one-half  to  an  inch  long  and 
one-quarter  to  three-eighths  of  an  inch  in  diameter, 
formed  (Fig.  14).  The  potatoes  may  be  held  at  this 
stage  for  some  weeks  if  necessary  by  lowering  the  tem- 
perature. Early  Rose  potatoes  weighing  about  three 
ounces  each  were  sprouted  as  described,  and  planted  on 
May   I  beside  similar  tubers  which  were  unsprouted. 


'  Kan.  Bui.  70,  p.  149,  and  Press  Bui.,  March  6,  1S99. 
*R.  I.  Bui.  36,  pp.  9  19. 


58 


THE   POTATO 


Part  of  the  crop  was  harv^ested  July  29,  the  yield  being 
decidedly  in  favor  of  the  sprouted  seed,  which  lead  was 
maintained  (see  Table). 

TABLE   IV 

YIEIvD  PER  ACRE  FROM  SEED  TUBERS  SPROUTED  AND   NOT 
SPROUTED 


Sprouted 

Not  sprouted. . 


Sprouted 

Not  sprouted. . 


Date 
Harvested 


July  29. . . 
July  29. . . 

Aug.  20. . 
Aug.  20. . 


YIELD   PER   ACRE 


Large 
Tubers 


Small 
Tubers 


Bushels  Bushels 

97.96        53.23 
76.10        42.78 


135-47 
94-45 


55-51 
41.90 


Total 


151-19 

118.88 

190.98 
136-35 


Gain  by 
Sprotiting 


Bushels 

32-31 


54-63 


Increase 

from 
Further 
Growth 


Bushels 


33-79 
'7-47 


In  trials  made  at  Cornell  Station  by  the  writer  dur- 
ing 1904,  with  the  varieties  Sir  Walter  Raleigh  and 
Carman  No.  3,  increased  yields  of  from  0.9  percent, 
to  73.7  per  cent,  resulted  from  sprouting  potatoes  in 
the  light  for  36  days  previous  to  planting,  when  com- 
pared with  holding  them  in  a  root-cellar  to  the  time  of 
planting.  The  sprouts  on  the  tubers  held  in  the  cellar 
were  up  to  three  inches  long;  those  held  in  the  light 
were  but  one-half  to  tliree-quarters  of  an  inch  long. 
No  misses  occurred,  except  from  those  sets  held  in  the 
cellar.  It  seems  probable  that  each  variety  may  have 
its  own  optimum  temperature,  as  conditions  were  uni- 
form for  both  varieties.  Eighteen  hills  were  used  in  a 
plat,  and  Table  V.,  on  page  59,  shows  the  results. 

Another  great  advantage  in  sprouting  is  that  it 
gives  an  opportunity  to  note  variation  and  "rogue" 
the  va.r\e\.y.  Almost  every  variety  shows  a  difference 
in   the  sprout,  either  in  color  or  habit  of  growth;  one 


CONSIDERATIONS    OF    SEED 


59 


may  have  a  white,  spiudly  stem,  which  becomes  green 
on  exposure;  another  a  short,  sturdy  stem,  which  be- 
comes bright  red;  while  another  may  be  purple,  and  so 
on.  So  far  I  have  found  the  ' '  sprouting  stage  ' '  the 
most  reliable  one  at  which  to  note  differences  in  varie- 
ties, and  varieties  of  potatoes  may  l^e  distinguished  as 
readily  as  varieties  of  other  crops. 

TABLE   V 


SIR    \\'ALTER    RALKIGH 

CARMAN   NO.  3 

Method  and 

Temperature 

of  Gertnination 

5     ^ 

YIELD 

2       ■§ 

YIELD 

of 
Plat 

1 

III 

Jo 

1"^ 

h  *  s 

I 

2 

3 
4    • 

Cellar  so-6o°F... 

Cold  Frame  bot- 
tom heat  So°F. 
sash  off 

Cellar  50-60°  F... 

Barn,  near  open 
window         45- 
7S°F  

2 

0 
0 

0 
0 

0 
0 

ij8 

330 
119 

100 
140 

127 
94 

Lbs. 

1-7 -50 

17.00 
16.20 

20.12 
17-50 

20.25 

15.75 

0.9 
19.4 

22.0 

0 

0 
0 

0 
0 

0 

I 

93 

I2S 
89 

122 
107 

85 
117 

Lbs. 

15-25 

26.5 
15-25 

21.25 
16.25 

16.25 
15.00 

- 
73-5 

36-9 

4-1 

6^ 

Cellar  50-60°  F... 

Greenhouse     78- 

90°  F 

7 

Cellar  50-60°  F. . . 

The  disadvantage  of  the  system  of  sprouting  pota'- 
toes  is  that  the  tubers  must  be  planted  by  hand  on  ac- 
count of  the  liability  of  knocking  the  sprouts  off  if 
passed  through  the  planter.  There  are  many  local 
markets  in  the  United  States  poorly  supplied  with 
early  potatoes,  and  to  supply  such  a  small  area  of  the 
crop  could  be  profitably  handled  as  above  described. 
A  distin(5lion  must  be  noted  between  the  above  method 


6o  THE    POTATO 

and  the  vSlovenly  practice  of  many  who  allow  their 
seed  tubers  to  send  out  long  sprouts  before  planting, 
which  are  either  broken  off  intentionally  before  or 
unintentionally  during  planting.  This  practice  cannot 
be  too  strongly  condemned. 

The  Trays  may  be  made  small  to  hold  40  pounds 
of  potatoes,  with  a  handle  running  lengthwise  across 
the  top,  or  to  contain  80  to  100  pounds,  and  handled 
by  two  men,  when  the  handles  run  across.  The  lum- 
ber for  the  trays,  ready  sawn  in  lengths,  should  be 
purchased  at  from  five  cents  to  ten  cents  per  tray, 
according  to  size. 

Whole  Sets  vs.  Cut  Sets. — Considerable  atten- 
tion has  been  given  to  the  advisability  of  cutting  seed 
tubers.  The  question  is  wholly  a  financial  one,  as  in 
an  average  year  with  an  ordinary  late  variety  the 
weight  of  the  seed  planted  is  of  more  importance  than 
whether  it  is  whole  or  cut.  Early  varieties  do  not  do 
so  well  w^hen  cut,  and  varieties  with  white  flowers 
seem  to  be  softer  in  texture  and  more  liable  to  failure, 
if  cut,  than  those  with  purple  or  colored  blo.ssoms. 
Some  varieties  cannot  be  cut  with  profit,  owing  to  lack 
of  bud-producing  eyes. 

The  labor  of  cutting  is  often  greater  than  the  cost 
of  the  extra  seed.  When  seed  is  expensive,  as  when  a 
variet}^  is  new,  it  is  wise  to  cut  as  far  as  possible  to 
secure  the  largest  possible  yield  in  the  least  time,  but 
this  course  must  be  followed  by  selecftion,  or  rapid 
deterioration  of  the  variety  will  result.  A  potato  cut 
into  single-eye  pieces,  and  each  piece,  planted  in  a 
hill,  will  give  a  greater  5deld  than  it  would  had  it  been 
planted  whole. 


CONSIDERATIONS  OF   SEED  6 1 

Time  to  Cut. — Formerly  it  was  advised  to  cut  the 
potatoes  a  few  da^'S  before  planting.  Generally  speak- 
ing, this  is  a  mistake.  Zavitz '  reports  as  the  result 
of  hundreds  of  trials,  during  a  period  of  eight  years, 
that  potatoes  cut  the  da}-  of  planting  gave  8  bushels 
per  acre  heavier  yield  than  those  cut  four  to  six  days 
before  planting.  Similar  results  were  obtained  at  the 
Montana  Experiment  Station.^ 

Size  of  Seed. — It  is  a  matter  of  general  observa- 
tion, supported  by  experiments,  that  large  seed  usually 
insures  a  larger  yield  than  small  seed.  This  may  be 
due  to  the  greater  amount  of  nourishment  furnished  to 
the  3'oung  plants,  which  enables  them  to  make  stronger 
growth,  and  to  the  greater  hereditarj'  vigor  possessed 
by  such  tubers.  Good-sized  seed  is  especially  desira- 
able  on  light  soils,  and  for  early  maturing  varieties. 
Smaller  seed  from  vigorous  plants  may  be  as  satisfac- 
tory with  late  varieties,  owing  to  their  longer  period 
of  growth.  The  advisability  of  using  large  or  small 
seed,  cut  or  whole,  depends  largel}'  upon  the  cost  of 
the  seed,  the  season,  the  culture  given,  and  the  price 
realized  when  harvested.  Generally  speaking,  tubers 
weighing  two  to  three  ounces  make  the  most  profitable 
seed,  as  they  are  worth  less  for  consumption.  The 
amount  of  experimental  work  which  has  been  under- 
taken to  decide  the  influence  of  the  size  of  the  seed 
tuber  upon  the  yield  is  enormous,  and  only  a  few  ref- 
erences can  be  given  here. 

Fischer,^  of  Germany,  advises   (i)  that  under  ordi- 


>  Ont.  Agr.  College  and  Farm  Report,  1S9S,  p.  15S;  1902,  p.  127. 

2  Mon.  Bui.  9,  p.  21.  =  E.  S.  R..  IX..  p.  331:  X.,  pp.  361-367. 


62  THE    POTATO 

nary  conditions  large  seed  should  be  used,  (2)  on  good 
soils  with  heavy  fertilizing  small  tubers  and  closer 
planting  is  advisable;  but  that  the  small  tubers  shall  be 
the  progenj^  of  large  tubers  grown  on  well-cultivated 
and  fertilized  soil,  to  prevent  degeneration.  Tubers 
which  are  small  because  the  parent  plant  had  not  suf- 
ficient vigor  to  produce  any  larger  are  worthless  for 
seed. 

At  Arkansas  Station'  whole  tubers  2  inches  to  3 
inches  in  diameter  jnelded  18  per  cent,  more  than  small 
whole  tubers  ^  inches  to  iJ/(  inches  in  diameter,  and 
large  cut  tubers  15.8  per  cent,  more  than  small  cut 
tubers.  At  the  Ontario  Agricultural  College^  the 
largest  yields  for  four  ^-ears  in  succession  Avere  from 
planting  large  seed.  Sets  weighing  one-sixteenth  of 
an  ounce  and  having  one  eye  5-ielded,  on  an  average, 
for  the  four  years,  44.2  bushels,  while  two-ounce  sets 
having  one  eye  averaged  177.4  bushels  per  acre,  and 
intervening  sizes  of  sets  yielded  in  proportion  to  their 
size.  As  the  result  of  eight  years'  careful  experi- 
ments, this  station  advises  that  large  tubers  be  cut  into 
pieces  wei-ghing  about  two  ounces  each  for  sets.' 

J.  C.  Arthur,^  of  Indiana,  condudled  an  elaborate 
set  of  experiments  for  three  j-ears  to  ascertain  the  rela- 
tion of  the  number  of  eyes  on  the  .seed  tuber  to  the 
produdl.  He  found  that  within  certain  limits  the  yield 
will  increase  with  an  increase  in  the  weight  of  the  set, 
and  that  the  exacl;  number  of  eyes  per  cutting  is  rela- 
tively unimportant.  With  tubers  of  the  same  weight 
and  variety  the  number  of  shoots  does  not  perceptibly 


1  Ark.  Bui.  50,  p.  28  2  Ont.  Agr.  Col.  Report,  1898,  p.  156. 

'  Ont.  Agr.  Col.  Report,  1922,  p.  126.      *  Ind.  Bui.  42. 


CONSIDERATIONS   OF   SEED  63 

increase  with  the  increase  of  eyes  on  the  tuber.  Seed 
tubers  weighing  iy4.  ounces  and  carrying  8  to  10  eyes 
sent  up,  on  an  average,  5.5  stalks  per  tuber,  while  seed 
tubers  weighing  3  ounces  and  having  14  to  18  eyes 
sent  up,  on  an  average,  11.3  stalks  per  tuber.  Bisect- 
ing an  eye  tends  to  increase  the  number  of  stalks,  be- 
cause each  e^e  is  usually  a  colledtion  of  buds,  and  some 
would  be  left  uninjured  on  each  piece.  The  number 
of  stalks  sent  up  tended  to  increase  with  the  size  of  the 
seed  tuber,  and  the  yield  increased  with  the  increase  in 
number  of  stalks. 

The  Virginia  Experiment  Station  '  reports  that  large 
seed  cannot  be  used  at  a  profit,  while  small  seed  is  not 
recommended,  but  that  sound  tubers  of  the  size  of  a 
hen's  ^gg  and  upward  are  proper  seed. 

Green,"  of  Ohio,  found  that  crops  from  whole  seed 
mature  a  few  days  earlier  than  from  the  same  sized 
seed  cut  in  two,  and  that  small  cuttings  require  the 
soil  to  be  in  better  condition  than  large  cuttings,  or 
whole  potatoes,  in  order  to  secure  a  good  stand  and  a 
profitable  crop. 

Amount  of  Seed  Per  Acre — Cost  and  Influ- 
ence on  Yield. — Plumb,'  of  Tennessee  Experiment 
Station,  found  the  largest  seed  tubers  to  be  most  pro- 
dudtiveand  the  least  profitable,  while  those  varying  in 
weight  from  one  to  three  ounces  were  most  profitable. 

At  Kentucky  Experiment  Station'  the  amounts 
planted  varied  from  six  bushels  per  acre  when  medium- 
sized  seed  were  cut  to  two  eyes  to  48  bushels  per  acre 
where   large   whole   potatoes   were   planted.     At  the 


'  Va.  Bui.  8,  p.  3.  iOhio  Second  Series  Bui.,  Vol.  III.,  I.,  p.  14. 

3Tenn.  Bui.,  Vol.  III..  I.,  p. 6.     *  Ky.  Bui.  22,  p.  136. 


64 

THE 

POTATO 

TABLE   VI 

YIELD    PER   ACRE 

Cost  oj 

Value  of 

Balance 

Amount 

IVcighl 
of  seed 

Distance 
planted 

seed  per 
acre  at 

crop  per 
acre  at 

ajter 

of  seed 

pa\ive 

peracre. 
Bushels 

tubers. 
Ounces 

apart. 
Feet 

Bushels 

Number 
of  Tubers 

75c.  per 
Bushel 

40c.  per 
Bushel 

for^ 
Seed 

64 

12-14 

3 

146 

90,980 

48.00 

58.40 

10.40 

81 

10-12 

2 

220 

135,075 

60.75 

88.00 

17.25 

66 

8-10 

2 

'95 

1 18. 102 

49-50 

78.00 

28.50 

52 

6-  8 

2 

168 

115.273 

39.00 

67.20 

28. 20 

37 

4-6 

2 

158 

108,908 

27.75 

63.20 

35-45 

26 

3-  4 

2 

146 

104,665 

19-50 

58.40 

38.90 

18 

2-  3 

2 

141 

81,328 

13.50 

56.40 

42-90 

11 

1-  2 

2 

128 

67,184 

8.25 

51-20 

42-95 

Michigan    Experiment   Station'    three   varieties   were 
tested,  with  results  as  shown  in  the  following  table: 


TABLE   VII 


SIZE   OF    SEED 

Amount  of  seed 
per  acre 

Yield 
per  acre 

Net  yield 

in  excess  of 

seed 

Net  gain 
from 
using 
halves 

Halves 

Quarters  .... 

Eighths 

Single  eyes  .    .    . 
Whole  tubers .  . 

Bushels             Lbs. 
20                    19 

9                     54 

5                    44 

4                     10 

41                    40 

Bushels 

317 
254 
221 
178 
293 

Bushels 
297 

.    244 
215 
174 
251 

Bushels 

53 
82 

1^ 

The  writer  has  found  from  seventeen  to  twenty 
bushels  to  be  necessary  to  furnish  a  good  seeding,  and 
others  have  advocated  the  same  amount,'  although  a 
less  quantity  is  frequently  mentioned  as  satisfadlorj-. 

A  compilation'  of  experiments  made  at  thirteen 
stations  to  determine  the  proper  amounts  of  seed  shows: 

I.  Within  ordinar}^  limits,  an  increase  in  seed  pro- 
duces a  marked  increase  in  total  yield  and  marketable 
potatoes. 


'  Mich.  Bui.  57,  p.  18. 


2  Mich.  Bui.  93,  pp.  5,  6. 


CONSIDERATIONS  OF  SEED  65 

2.  An  increase  in  the  size  of  the  seed  from  one  eye 
to  half  a  potato  produces  an  increase  in  the  net  value 
of  the  crop. 

A  comparison  of  the  half  potato  with  the  two  e5^es 
shows  that : 

1.  For  the  total  yield  (large  and  small)  of  95  ex- 
periments, 76  are  in  favor  of  the  half  potato  and  19 
in  favor  of  two  eyes. 

2.  For  marketable  yield  (total  less  small)  of  73  ex- 
periments, 58  are  in  favor  of  the  half  potato  and  15  in 
favor  of  the  two  eyes. 

3.  For  net  marketable  yield  (marketable  less  amount 
of  seed)  of  30  experiments,  23  are  in  favor  of  the  half 
potato  and  7  in  favor  of  the  two  eyes. 

4.  For  net  value  of  crop  (value  of  crop  less  value  of 
seed)  of  30  experiments,  22  are  in  favor  of  the  half 
potato  and  8  in  favor  of  two  eyes. 

A  comparison  of  the  whole  potato  with  the  half 
potato  shows  that : 

1.  For  the  total  jaeld  (large  and  small)  of  54  ex- 
periments, 46  were  in  favor  of  the  whole  potato  and  8 
in  favor  of  the  half  potato. 

2.  For  the  marketable  yield  (total  less  small)  of  42 
experiments,  36  were  in  favor  of  the  whole  potato  and 
6  in  favor  of  the  half  potato. 

3.  For  the  net  marketable  yield  (marketable  less 
amount  of  seed)  of  13  experiments,  7  are  in  favor  of  the 
whole  potato  and  6  in  favor  of  the  half  potato. 

4.  For  the  net  value  of  crop  (value  of  marketable 
less  value  of  seed  planted)  of  12  experiments,  7  are  in 
favor  of  the  whole  potato  and  5  in  favor  of  the  half 
potato. 


66  THE   POTATO 

The  Value  of  Bud  and  Stem  Ends  and  the 
Middle  of  the  Tuber  for  Seed. — Many  ideas  have 
prevailed  as  to  the  relative  values  of  different  parts  of 
the  tuber,  for  seed.  Some  growers  advocate  the  re- 
moval of  one  end  or  the  other,  but  thus  far  the  ex- 
periments conducfted  at  a  dozen  stations,  including  such 
varying  points  as  Illinois,'  New  Jersey,^  and  North 
Dakota'  Experiment  Stations,  show  that  there  is  no 
material  difference  noticable  in  yield  that  could  be  at- 
tributed to  the  different  pieces,  and  that  the  two  ends 
of  a  tuber  are  pradlically  of  equal  value. 

Viability. — The  buds  of  tubers  varj^  considerabl)^  in 
their  ability  to  grow,  and  the  same  is  true  of  the  tubers 
themselves.  Goff,  of  Wisconsin,'  when  using  the  vari- 
ety Burbank,  obtained  a  stand  varying  from  88  to  loo 
per  cent,  of  the  potatoes  planted.  The  importance  of 
proper  moisture  content  of  the  soil  is  shown  by  the 
results  reported  in  the  following  table  by  Woods,  of 

Maine:' 

TABLE  VIII 

VARIETY  STAND 

Percentage  of  Ciitlings 
that  Produced  Plants 

Rose        22 

Early  Michigan 46 

Hulett's  Rust  Proof 37 

Mill's  Mortgage  Lifter 20 

Green  Mountain 61 

New  Queen i 

Polaris 55 

Maggie  Murphy 50 

Irish  Cobbler 65 

Early  Ohio 57 

Gem  of  Aroostock 28 

Bovee 55 

'  111.  Bui.  40,  p.  132.  »  N.  J  Report,  iSyS.  p.  30S.  »  N.  D.  Report,  1901, 
pp.  40-42.      •»  Wis.  Report,  1897,  p.  306.       "*  Me.  Bui.  98,  p.  1S3. 


CONSIDERATIONS   OF   SEED 


67 


This  poor  stand  was  largely  due  to  a  verj-  dry  spell 
in  Maj'  and  June,  and  the  differences  observed  in  the 
various  varieties  may  be  due  to  the  vitality  of  the  vari- 
eties themselves,  or  to  the  way  in  which  the}'  were 
grown  and  stored,  or  to  both  causes.  Girard,  of 
France,  summarized  his  experiments  some  time  ago, 
showing  the  influence  of  the  size  of  the  tuber  upon  the 
' '  stand  ' '  and  yield. 

TABLE  IX 


WEIGHT   OF  SEED 


I — Tubers    3.5  oz.  each,  planted  whole    .... 
2 — Tubers    .^.5  oz.  each,  cut  into  two  portions 
3— Tubers    7.0  oz.  each,  cut  into  two  portions  . 
4 — Tubers  10.5  oz.  each,  cut  into  three  portions 
5 — Tubers    1.75  oz.   each,   two  tubers   planted 

together   

6 — Tubers    i.o  oz.  each,   three  tubers  planted 

together 


Percentage 

Number  of 

Failures 


6.0 
12.0 
10.5 
14-5 

3-7 

3-7 


Percentage 

Weight  of 

Crop 


100.00 
69.36 
82  00 
74.00 

95-36 
89.12 


The  yield  of  No.  2  is  not  comparable  with  the 
others,  because  the  same  weight  of  seed  was  not  used. 
Plats  I  and  3  are  probably  the  best  to  use  for  ordinary 
consideration,  and  would  show  that  from  90  to  95  per 
cent,  of  the  tubers  planted  should  grow,  but  it  is  a 
well-known  observation  that  under  adverse  conditions 
— as,  a  dry  season,  ill-fitted  land,  etc. — a  small  cutting 
is  not  so  likely  to  grow  as  a  whole  tuber. 

The  diagram  (Fig.  16)  .shows  that  with  Carman  No. 
3,  where  twenty  plats  were  noted,  there  were  3  chances 
in  20  that  the  germination  of  the  tubers  and  stand 
would  be  100 per  cent.,  and  that  it  is  much  more  likely 
to  be  between  91    and  98    per  cent,   than  any   other 


68 


THE   POTATO 


^ 

— 

9 

\ 

/ 

- 

-/ 

\ 

\ 

/^ 

/ 

\ 

^ 

/ 

\ 

/ 

\ 

A 

10 

d  9 

9  3 

8  5 

7  5 

65 

5  9 

n 

Z  5/  5tf  89  88  87  8 

6  85  84  83  82  81  80  79  78  77  76  li 

J.-,,;.   i6 — DIAGRAM    SHOWING   STAND    OF   TWENTY    PLATS    OF 

CARMAN    NO.    3    POTATOES' 

The  percentage  stand  is  shown  on  the  base-line.    The  hight  of  the  cuive 

from  the  base-line  shows  the  actual  number  of  plats. 


m 


1 


9876    4321     9  8  7  6    4  32  I   ^9  8  7  6_-4  3  2  /     9  8  76    43  2  ;     9  8  7  6 
m  35  90  85  80  75  70  65  60 

FIG.   17 — DIAGRAM    SHOWING   STAND   OF   THIRTY-SIX    PLATS 

OF    EARLY    TRUMBULL    POTATOES' 

The  percentage  stand  is  shown  on  the  base-line.     The  hight  of  the  curve 

from  the  base-line  shows  the  act\ial  number  of  plats. 

number,    although  the  average  as  usually  worked  out 
would  show  93.5  per  cent. 

With  Early  Trumbull,  using  seed  showing  the  rosette 
disease  {^Rhizodonia  solani)  and  some  not  showing  it, 
treated  with  various  fungicides,  the  average  germina- 


1  From  data  in  Ohio  Bui.  145,  p.  21. 


CONSIDERATIONS   OF   SEED  69 

ting  power  for  36  plats  is  73. 8  per  cent.  Yet,  here  again 
this  does  not  convey  a  true  impression,  as  on  six  plats 
all  of  the  tubers  germinated,  and  the  table  shows  that 
there  is  a  greater  chance  of  securing  a  stand  of  between 
83  and  98  per  cent,  than  lower.' 

The  viability  of  tubers  is  injured  or  ruined  if  they 
heat  or  sweat  to  any  extent;  hence,  if  they  have  been 
treated  with  a  solution,  as  for  scab,  it  is  essential  that 
they  be  planted  at  once  or  spread  thinly  to  dry.  Po- 
tatoes may  be  ruined  for  seed  purposes,  if  frozen,  or  if 
shipped  in  bags  or  barrels  which  have  contained  sub- 
stances injurious  to  the  buds — as,  sugar,  nitrate  of  soda, 
etc. ;  and  even  moving  them  on  the  farm  in  unwashed 
sugar-bags  has  been  found  to  be  dangerous.  Immer- 
sion in  water  for  more  than  a  day  may  destroy  the 
buds,  and  probably  cause  the  tuber  to  decay  in  a  few 
days.  By  this  means  potatoes  have  been  destroyed  in 
pits  and  in  the  field  when  floods  have  occurred.  Soak- 
ing them  in  too  strong  a  solution  of  formalin  or  other 
preservative  is  liable  to  reduce  viabilit}',  because  the 
formalin  tends  to  preserve  the  tuber  and  prevent  its  de- 
composition. 

Potatoes  which  have  been  subjedl  to  diseases  may  be 
weakened  and  their  vitality  impaired. 


1  From  data  in  Ohio  Exp.  Sta.  Bui.  145,  p.  21. 


CHAPTER  VII 

VARIETIES 

Selecting  a  Variety. — For  general  farming  it  is 
advisable  to  grow  only  a  few  varieties.  Most  success- 
ful growers  seldom  have  half  a  dozen  growing  for  mar- 
keting, and  usually  one  is  selected  as  more  suitable 
than  the  rest.  The  beginner  is  advised  to  seledl  a 
variety  from  the  more  thoroughly  tested  kinds  that 
have  done  well  in  his  immediate  vicinity  and  on  his  type 
of  soil.  The  seed  should  be  obtained  from  a  reliable 
grower  or  a  respon.sible  seedsman.  The  importance 
of  growing  the  best  varieties  cannot  be  too  strongly 
emphasized.  To  many  a  potato  is  a  potato,  and  any- 
thing is  used  for  seed.  Such  haphazard  methods 
cannot  survive.  Potatoes  are  grown  for  human  con- 
sumption, and  the  public  taste  must  be  considered. 
Good  quality  and  good  yield  are  required.  In  some 
localities  good  quality  potatoes  appear  to  be  grown  in 
spite  of  adverse  conditions,  but  not  all  of  the  crop  can 
be  produced  in  this  way. 

Some  of  the  points  to  consider  in  sele(5ting  the 
variety  are  : 

1 .  Good  cooking  qicality  and  flavor.     This  is  partly 

influenced  by  the  soil,  season,  ability  to  mature 
before  frost,  etc. 

2.  The  yield.     The  late  maturing  varieties  usually 

yield  heavier  than  the  early  varieties.     Yield  is 
influenced,  among  other  things,  bj-  the  adapta- 
bility of  the  variety  to  the  distri(5l  and  soil. 
70 


VARIETIES  71 

3.  Ability  to  resist  diseases.     The  potato  is  so  sub- 

jedt  to  disease  that  this  is  now  of  prime  impor- 
tance in  a  variety  in  the  Eastern  States,  although 
not  so  important  in  parts  of  the  Trans- Missis- 
sippi area. 

4.  T/ie  color  of  the  skin  a7id  tuber.     In  the  Eastern 

States  red  varieties  are  not  in  favor  at  present, 
a  white-fleshed  and  white-skinned  tuber  being 
preferred.  In  the  South  red-skinned  varieties 
are  sought.' 

5.  The  natiire  of  the  skin.     A  netted,  or  rough,  skin 

is  preferred. 

6.  The  shape.    Some  markets  discriminate  in  favor 

of  a  particular  shape,  the  flat-round  and  oval 
generall)'  being  popular  shapes. 

7.  The  depth  and  frequency  of  eyes.     Potatoes  with 

deep  and  numerous  eyes  are  not  economical  in 
preparation  for  cooking. 

8.  The  time  of  maturity .     This  is  essential  to  know 

before  planting,  in  order  to  facilitate  the  dis- 
tribution of  farm  work  and  determine  whether 
it  is  likely  to  mature  in  the  locality. 

9.  The  hazilm. 

10.  The  leaf. 

11.  The   vigor  of  the   variety.      This   is   important, 

although  it  is  of  equal  importance  to  obtain  a 
vigorous  strain  of  a  variety,  as  wide  variations 
are  noted  in  the  same  variety. 

12.  Tendejicy  to  viake  second  growth. 

'  Tex.  Bui.  71,  p.  9. 


72 


THE   POTATO 


13.    Trueness  to  type.       It  is  essential  that   the  seed 
be  as  represented.     As  none  but  an  expert  can 

tell  the  different 

varieties    apart, 

seed   should    be 

obtained  from  a 

reliable    grower 

or  a  responsible 

seedsman. 

I.    Cooking  quality 

aiid  flavor  are  two  of 

the      fa(5tors     which 

determine     culinary 

value.        They      are 

distinct.         Cooking 

quality  is  recognized 

in  a  boiled  potato  b}- 

mealiness   or    soggi- 

ness.      This  appears 

P-Envelope,  or  Periderm,  consisting  of  an  tO  depend  UpOU  the 
inner  and  outer  layer.  />./,- Pigment  layer,  physioloffical  StrUC- 
where  coloring-matter  of  the  skin  is  found.       • 

£.C-ExternaI  Cortical,  or  Cambium  layer,  tUrC  of  the  tubcr,  and 
usually  poor  in  starch.  /.C— Internal  Cor-  ig  not  neCeSSarllv  COll- 
tical,  or  Cambium  layer,  rich  in  starch.    E.M 

—External  Medullary  layer,  rich  in  starch.   neCtcd  witll  chcmical 
/.il/— Internal   Medullary  layer,  or  pith,  or  romOOsitioil         T Pie's 
water-core,  poor  in  starch. 
The  objectionable  features  of  this  tuber  are    18,      1 9).  A    potatO 

large  pith  area  and  lack  of  uniformity  in  showiug  Uniformity 
cellular  structure.     Each  layer  is  readily  rec-  . 

ognized,  and  each  one  varies  in  the  amount  of  ^  tlie  distribution  OI 
time  required  forcooking;  hence,  it  is  of  poor  gtarch  ill  the  VarioUS 
cooking  quality.     (Compare  with  Fig.  19. ) 

layers  may  be  con- 
sidered to  be  of  better  quality  than  one  not  showing 
this  uniformity.     Immature  potatoes  tend  to  be  soggy 


FIG.    10 — SECTION  OF  A   POTATO  OF 
POOR    COOKI.NG    QUALITY 


VARIETIES 


73 


when  cooked, 
starch  grains  in  a 
ture  of  the  cell 
walls  during  cook- 
ing. Sogginess 
occurs  when  the 
cell  walls  retain 
their  form.  Opin- 
ions differ  as  to 
what  constitutes 
good  cooking 
quality.  Amer- 
icans like  a  white, 
mealy,  or  fiour)^ 
potato.  The 
French  prefer  a 
yellow,  sogg)' 
potato  which  re- 
tains its  shape 
when  boiled. 

Good  cooking 
quality  can  be  de- 
termined by  cook- 
ing.  The  common 


Mealiness  is   due  to  the  union  of  the 
cell  into  one  mass,  and  the  rup- 


FIG.    19 SECTION    OF   A    POTATO    OF 

GOOD  COOKING  QUALITY 
(Compare  with  Fig.  iS.) 
The  desirable  features  of  this  tuber  are  well- 
netted  skin,  showing  maturity;  large  Internal 
Cortical  (/.C'.)and  External  Medullary  (iT.il/.) 
layers,  which  are  rich  in  starch  ;  small  pith 
area  {I.M.),  with  marked  uniformity  in  cellu- 
lar structure.  The  different  layers  nearly  ap- 
proach each  other  in  appearance,  and  cook 
uniformly. 


method  is  to  take 

a  sample  and  steam  or  boil  some  of  the  potatoes. 
When  cooked 'the  potato  .should  be  dry  and  floury,  free 
from  wetness,  and  readily  break  to  pieces  on  slight 
pressure,  or  be  readily  reduced  to  a  coarse  meal  free 
from  hard  lumps.  The  particles  should  glisten  as 
though  crystalline,  and  the  potato  should  have  a  white 
color,  which  is  retained  when  cold.     Potatoes  which 


74  THE   POTATO 

are  yellow  when  cooked,  or  turn  dark  or  black,  are 
not  considered  of  good  quality,  even  if  the  flavor  is 
good,  and  can  be  sold  only  to  a  low-class  trade. 
Tubers  must  not  be  hollow  in  the  center,  as  this  gives 
rise  to  a  hard,  dark-colored  core,  which  is  decidedly 
objectionable  if  potatoes  are  to  be  mashed. 

Some  varieties  will  cook  better  if  they  have  been 
kept ;  they  are,  in  other  words,  for  spring  use.  Thus, 
in  New  York,  Carman  No.  3,  White  Star,  and  Doe's 
Pride  come  in  this  category. 

The  flavor  should  be  mild,  and  free  from  earthiness. 

2.  The  yield.  The  average  yield  of  potatoes  from 
one  plant  in  the  United  States  is  about  half  a  pound. 
Having  weighed  the  j'ield  of  hundreds  of  potato 
plants  during  the  past  year,  we  find  that  in  the  case  of 
Early  Ohio  one  plant  yielded  three  tubers  weighing 
half  an  ounce,  while  another  yielded  thirteen  tubers 
weighing  two  and  a  half  pounds.  The  latter  yield  is 
eighty  times  the  former.  In  late  varieties  plants  yield- 
ing four  pounds  of  tubers  were  found.  In  some  of  the 
recent  English  productions  whole  plats  would  average 
six  pounds  of  tubers  per  plant,  while  individual  plants 
have  yielded  over  twenty  pounds  of  potatoes,  as  man)' 
as  150  potatoes  being  set  on  one  plant.'  These  fa(5ls 
emphasize  the  value  of  the  farmer  seledling  seed  him- 
self and  eliminating  the  poor  plants.  All  the  tubers 
from  the  best  plants  should  be  saved  and  planted  sep- 
arately to  produce  the  seed  for  the  following  3ear. 
The  expenses  of  growing  a  poor  and  a  heavy  crop 
vary  little.     The  onl}-  additional  cost  of  the  latter  is 


'  Gardener's  Chronicle,  Oct.  15,  1904,  pp.  276-278. 


VARIETIES  75 

a  little  more  for  digging.  The  variety  controls  the 
yield  to  a  large  extent,  and  there  is  much  more  like- 
lihood of  obtaining  a  300-bushel  crop  from  a  variety 
capable  of  yielding  600  than  from  one  whose  maxi- 
mum yield  is  300  bushels.  This  fa  (ft  is  realized, 
and  the  high  prices  paid  in  recent  years  in  Great 
Britain  for  seed  potatoes  of  good  quality,  heavy  yield- 
ing, and  disease-resisting  varieties  are  legitimate  and 
proper  recompense  to  the  men  who  have  the  skill  to 
breed  such.  These  new  varieties  are  profitable  to 
grow  because  there  is  an  assurance  that  the  crop  will 
yield  well,  and  that  it  will  keep  well;  hence  there  is  an 
opportunity  to  hold  it  until  it  can  be  sold  at  a  profit. 
These  farmers  realize  that  the  best  is  none  too  good, 
and  that  it  is  useless  handling  varieties  that  are  out  of 
date.  The  potato  grower  of  Great  Britain  and  Europe 
must  be  up  to  date  if  he  is  to  stay  in  the  business. 
High-priced  seed  receives  more  care  in  storage  and  is 
handled  more  intelligently,  the  seed-bed  is  better  pre- 
pared, and  the  result  is  better  farming.  The  farmer 
who  grows  such  crops  is  a  more  thoughtful  and  better 
business  man,  as  slovenly  methods  have  to  be  aban- 
doned. 

Yield  is  influenced  by  the  size  and  number  of  tubers 
at  a  root.  Uniformity  and  good  size  are  desired. 
Potatoes  vary  in  size  from  almost  nil  to  six  pounds 
each  or  more.  In  Doe's  Pride  one  plant  set  21  tubers, 
varying  in  size  between  i-io  ounce  and  6^  ounces; 
in  other  words,  one  potato  was  65  times  larger  than 
the  other.  In  the  East  potatoes  over  8  ounces  in 
weight  are  large.  Medium-sized  tubers  of  merchant- 
able value  var}^  between  four  and  eight  ounces.     Sec- 


76  THE    POTATO 

onds  between  two  and  four  ounces,  and  tubers  less 
than  this  weight,  are  hardly  worth  picking  up. 

3.  Ability  to  resist  diseases.  No  varieties  can  be 
termed  ' '  disease  proof, ' '  but  many  varieties  are  better 
disease-resisters  than  others.  Stuart,  of  New  Hamp- 
shire, found  that  the  variety  Hulett's  Rust  Proof  was 
the  only  one  that  was  disease-resistant  out  of  several 
varieties,  although  the  varieties  Dakota  Red,  Green 
Mountain,  New  Queen,  and  Enormous  showed  some 
resistance.  Hulett's  Rust  Proof  falls  below  the  re- 
quirements in  other  respe(5ls  and  is  of  little  value,  and 
in  Minnesota  has  been  found  to  be  subjedl  to  disease. 
At  Ontario  Agricultural  College,  Carman  No.  3  and 
Stray  Beauty  resisted  disease  well.  At  Minnesota 
Exp'eriment  Station,  Rural  New  Yorker  and  Sir  Wal- 
ter Raleigh  showed  some  resistance.- 

4,  The  color  of  the  skin  and  tuber.  Many  of  the 
colored-skinned  varieties  of  potatoes,  and  those  show- 
ing a  blush  of  pink — as,  the  Beauty  of  Hebron,  Early 
Rose,  etc. — belong  to  a  type  which  have  white  blooms. 
The}^  are  generall}^  early  maturing,  rather  liable  to  dis- 
ease, and  of  good  qualit}',  according  to  the  American 
standard.  The  colored-.skinned  early  varieties  are  gen- 
erally more  readily  sold  than  the  late  ones,  although 
in  some  districts  colored-skinned  potatoes  are  not  ob- 
jected to  on  the  market.  All  colored-skinned  potatoes 
are  not  deficient  in  vigor.  Some  are  among  the  best 
di.sease-resisting  and  best-flavored  varieties,  but  the 
red  color  of  some  weak  varieties  has  rendered  some 
growers  skeptical  of  all. 


Minn.  Bill.  IS7,  p.  2.  ^  Minn.  Bnl.  S7,  p.  10. 


78  THE   POTATO 

5.  The  nature  of  the  skill.  The  skin  may  be  thick, 
medium,  or  thin.  Some  growers  claim  that  thick- 
skinned  varieties  are  of  better  quality  than  thin-skinned 
ones,  but  such  correlation  does  not  always  exist. 
Potatoes  grown  on  sandy  soils  usually  have  smoother 
skins  than  those  grown  on  heavy  loams.  Some  va- 
rieties develop  a  netted,  or  rough,  skin  as  they  mature 
in  storage,  although  such  may  not  be  apparent  at 
harvest-time.  The  rough,  or  netted,  skin  in  these 
cases  appears  to  denote  maturity,  and  this  may  account 
for  the  common  idea  that  a  rough-skinned  potato  is  of 
good  quality.  The  size  and  type  of  netting  (Fig.  20) 
varies  with  the  variety,  and  the  conditions  under 
which  it  is  grown. 

6.  The  shape.  Most  of  the  recent  introductions, 
exclusive  of  the  Early  Rose  type,  have  had  a  tendency 
to  partake  of  the  fiat-round  or  oval  (Fig.  21).  These 
shapes  have  been  sought  because  such  potatoes  appear 
to  be  of  better  quality  consistent  with  an  economical 
shape  and  shallow  eyes.  The  probable  explanation  is 
that  in  a  flat-round  orthinni.sli  potato  there  is  a  greater 
surface  in  proportion  to  the  bulk.  The  greater  the 
surface  the  larger  the  percentage  of  the  tuber  taken 
up  in  the  cortical  layer  and  outer  medullary  layer  (Fig. 
18).  These  are  the  starch-bearing  areas,  and  as  they 
are  increased  the  inner  medullary  layer,  or  pith,  which 
has  little  starch,  is  dimini.shed,  thus  rendering  the 
potato  more  uniform.  Whatever  shape  is  desired  can 
be  be  obtained,  but  a  potato  should  be  true  to  shape. 
The  tendency  of  a  tuber  to  become  pointed  or  drawn 
out  at  the  tip  or  butt  end,  especially  if  the  variety  is 
a  flat-round  or  round,  indicates  lack  of  vigor  (Fig.  21). 


VARIETIES 


79 


7.  Depth  a7id  frequency  of  eyes.    Deep  eyes  (Fig.  21), 
to  some  extent,  are  regarded  as  associated  with  robust- 


KIG.    21 THREE    FAVORITE    SHAPES    OF    POTATOES 

{Upper  row,  the  broad  surface  ;  lower  rozc,  the  narrow  surface.) 
Beginning  on  the  right,  the  small  one  is  a  flat-round;  the  center  one,  kid- 
ney; the  largest  one,  on  the  left,  elongated  oval.     Notice  the  shallow,  wide 
eyes  on  the  latter;   they  are  the  most  desirable.     The  eyes  of  the  flat-round 
are  too  deep.  ' 


ness  and,  frequently,  coarseness.  They  are  wasteful 
in  peeling.  Deep  eyes  tend  to  hold  moisture,  which 
hastens  decay  when  the  potatoes  are  stored. 

8.    Tifuc  of  viaturity.     In  the  Northern  States  pota- 


8o 


THE    POTATO 


toes  are  classified  into  early,  medium  or  second  early, 
and  late  varieties,  according  to  the  time  they  take  to 
reach  maturity.     Early  varieties  may  mature  in  70  to 


FIG.  22 — THE    IMPORTANCE    OF    HAVING    ri'RIGHT    HAULM    AND 
PRESERVING    THE    FOLIAGE    IS    NOT    SUFFICIENTLY    APPRECIATED 

Plant  photographed  early  in  September,  1904,  when  many  others  near  were 
dead  (C.  U.  Farm).     Upright  haulm  facilitates  late  cultivation  and  spray- 
ing.    The  foliage  dri^s  quickly,  and  then  is  not  so  favorable  for  the  growth 
of  spores  of  rot. 

90  days  after  planting  ;  second  earlies,  in  90  to  130 
day^,  while  late  varieties  may  continue  to  grow  for 
200  days. 

9.  The  haulm.  The  haulm  and  leaf  are  receiving 
more  attention  to-da}'  than  formerly.  The  size  of 
haulm  has  an  influence  upon  the  distance  apart  of 
planting.     Large  haulm  is  more  trouble  to  .spray,   re- 


VARIETIES  8l 

quiring  more  solution,  and  it  is  alwa)^s  lying  over  the 
ground  when  the  last  spraying  ought  to  be  given,  and 
is  in  the  way  at  lifting-time,  whether  the  potatoes  are 
raised  by  hand  or  digger.  Modern  breeders  aim  to 
produce  a  short  haulmed,  upright,  heavily  leaved  top, 
because  the  upright  habit  of  growth  (Fig.  22)  is  more 
likely  to  keep  clear  of  disease  than  a  spreading  habit, 
owing  to  water  being  shed  from  the  former  more  read- 
ily than  from  the  latter,  and  not  offering  a  foothold  to 
the  disease  spores  (Fig.  37).  Plants  whose  branches 
lie  on  the  ground  are  more  liable  to  disease  because 
they  cover  a  greater  area,  their  leaves,  touching  the 
ground,  are  almost  always  damp  from  contacfl  with  it, 
and  sun  and  wind  cannot  so  readily  reach  them.  \'ery 
tall  haulmed  varieties  are  readily  beaten  down  by 
storm  and  wind,  and  in  this  state  they  cannot  dry  so 
readily;  hence,  they  fall  in  a  clammy  mass,  v^ery  favor- 
able for  the  growth  of  disease  spores. 

Varieties  with  strong,  hardy  haulm  suffer  less  from 
spring  frosts.  Late  varieties  usually  have  taller  haulm 
than  first  early  varieties.  Some  varieties  make  their 
heaviest  growth  of  foliage  late  in  the  season,  and  in 
this  way  are  not  so  subjedl  to  attacks  of  early  blight. 

10.  The  leaf.  The  British  disease-resisting  varieties 
have  hard,  thick  leaves.  Whether  the  thickness  of  the 
leaf  is  an  important  fadtor  in  their  resistance  to  rot  {Phy- 
tophthora  infestans)  is  not  determined.  The  fadl  that 
spraying  the  upper  surface  of  the  leaf  tends  to  prevent 
blight  would  seem  to  show  that  access  to  the  inside  of 
the  leaf  is  obtained  by  growth  through  the  cell  walls 
as  well  as  through  the  stomata,  on  its  under  surface. 
If  this   be  true,  then  the    thickening  and  hardening 


82  THE   POTATO 

of  the  cuticle  and  the  palisade  cells  (Fig.  34),  or 
thick  cells  on  the  upper  surface  of  the  leaf,  will  no 
doubt  prevent  many  spores  from  reaching  the  inside 
cells  of  the  leaf.  They  may  germinate  on  the  surface, 
but  not  enter,  unless  they  find  some  place  where  the 
leaf  has  been  injured.  The  pundtures  of  the  flea- 
beetles  are,  on  this  account,  of  great  importance,  as 
they  furnish  an  entrance  to  the  inner  cells  (Fig.  40). 

N.  A.  Cobb,  of  Australia,  has  shown  that  in  the 
case  of  wheat  the  varieties  most  resistant  to  rust  {Puc- 
cinia  graminis  ?i\\^  P.  riibigo  vera),  none  being  abso- 
lutely resistant,  have  narrow,  stiff,  upright  foliage, 
while  those  most  liable  to  attacks  have  broad,  flabby, 
and  pendant  foliage.  In  the  plants  resistant  to  rust 
the  cuticle  of  the  leaf  is  much  thicker  than  in  the 
others,  and  is  so  thick  that  the  rust  spores,  when  they 
germinate  on  the  outside  of  the  leaf,  cannot  penetrate 
it,  or  if  they  do  succeed  in  entering  the  leaf  through 
storaata,  the  threadlike  growths  of  the  parasite  cannot 
rupture  the  cuticle  wall  to  fructify  ;  and,  further,  some 
wheats  have  stomata  so  narrow  and  are  so  well  cov- 
ered with  wax  that  the  germinating  threads  of  the 
rust  spore  fail  to  enter  every  time.  These  circum- 
stances seem  to  support  the  claim  that  the  tough,  thick- 
walled,  hard,  dry  leaf  is  the  one  to  selecft  for  di.sease- 
resistant  powers.  It  has  been  observed  that  plants  of 
the  potato  family  having  this  type  of  leaf  are  fairly  free 
from  fungus  leaf  diseases.  It  is  essential  that  the 
leaves  of  the  potato  be  abundant  to  in.sure  a  good  yield. 

1 1 .  The  vigor  of  the  variety.  Vigor  is  the  power 
stored  in  a  plant  which  enables  it  to  overcome  difficul- 
ties at  different  periods  of  growth.     A  variety  must 


VARIETIES  83 

have  vigor.  If  not,  it  may  fail  to  establish  itself  dur- 
ing the  early  part  of  its  career,  being  a  shy  budder  ; 
it  may  be  readily  injured  by  frost,  heat  or  cold, 
drouth  or  a  wet  period,  and,  having  little  recuperative 
power,  will  give  small  returns  for  the  labor  bestowed 
upon  it.  If  it  survives  to  tuber- formation  time  it  will 
probably  fail  then.  Plants  or  varieties  showing  lack 
of  vigor  must  be  discarded.  Some  varieties  have  short 
staying  power;  they  appear  to  be  vigorous  for  one  or 
two  years,  and  then  suddenly  collapse.  Others  have 
great  staying  power — as.  Early  Rose,  which  has  been 
prominent  for  over  forty  years. 

The  statement  is  sometimes  made  that  modern  vari- 
eties are  not  so  long-lived  as  their  ancestors — that  they 
are  deficient  in  staying  power.  If  the  statement  were 
true,  it  might  be  explained  by  saying  that  new  vari- 
eties are  produced  more  frequently,  and  that  on  account 
of  their  heavier  yielding  power  or  better  quality  they 
displace  the  old  ones.  The  fadts  seem  to  show  that 
modern  potato  breeders  have  more  than  maintained 
vigor  and  staying  power.  Hays,  of  Minnesota,  and 
others,  place  the  life  of  a  good  modern  variety  at  about 
thirty  years.  This  seems  to  be  accepted  by  many, 
both  here  and  abroad.  Dr.  Hunter,  of  England,  in 
his  "  Geological  Essays,"  '  writing  about  one  hundred 
years  ago,  states  ' '  that  varieties  continue  in  vigor 
about  fourteen  years,  after  which  the  produce  gradually 
declines."  ShirrefF  and  T.  A.  Knight  held  similar 
views  ;  the  latter  wrote "  that   ' '  not  a  single  healthy 


'  "Geological  Essays,"  Exp.  14,  p.  348. 

-  Hort.  Trans.,  Vol.  I.,  and  Miller's  "  Gardeners' Dictionary,"  ed.   i5 
'Potatoes." 


84  THE    POTATO 

plant  of  any  sort  of  potato  that  yields  berries,  and 
which  was  in  culture  twenty  years  ago,  can  now  be 
produced."  So  late  as  1838  this  idea  was  accepted  by 
the  horticulturists  of  England.'  It  is  interesting  to 
note  that  the  average  yield  of  potatoes  in  England  a 
hundred  years  ago  is  stated  to  vary  between  185  and 
300  bushels,  and  sometimes  440  bushels,  per  acre. 
The  average  yield  to-day  is  about  230  bushels,  but 
some  growers  produce  750  bushels  per  acre  frequently. 
The  average  improvement  in  the  quality  of  the  tubers 
is  greater  than  the  average  improvement  in  yield. 
Formerly  the  potatoes  were  grown  largely  for  stock, 
and  were  of  poor  flavor  and  bad  cooking  quality. 

Some  new  varieties  make  vigorous  growth,  and,  be- 
coming bark-bound,  the  skin  cracks.  Such  varieties 
are  regarded  as  of  coarse  and  inferior  quality,  and  lack- 
ing in  appearance.  This  chara(5ler  may  be  eliminated 
by  judicious  sele<5lion.  Deficiency  in  vigor  is  indi- 
cated by  the  formation  of  misshapen  tubers  drawn 
out  at  either  end,  the  presence  of  second  growth,  weak 
buds,  lack  of  uniformity  in  texture — as,  hardness  at 
the  ends  of  the  tubers  when  cut,  especially  brittleness 
of  texture.  Tubers  showing  any  such  chara(5leristics 
should  not  be  planted. 

When  potatoes  are  planted  15  inches  apart  in  36- 
inch  rows,  there  are  11,616  plants  per  acre.  If  each 
plant  had  sufficient  vigor  to  yield  three  tubers,  each 
weighing  half  a  pound,  or  four  weighing  six  ounces 
each,  a  j-ield  of  290  bushels  of  salable  potatoes  per 
acre  is  assured.  No  one  can  afford  to  use  seed  of  less 
vigor  than  this. 

1  Don's"  Gardeners'  Dictionary,"  183S,  Vol.  IV.,  pp.  400-406. 


VARIETIES  85 

12.  Tendency  to  make  second  growth.  Second  growth 
(Fig.  38)  is  most  prevalent  in  a  season  when  drouth 
is  followed  by  a  wet  period.  The  drouth  checks 
the  development  of  the  tubers,  causing  them  to  begin 
to  mature,  while  the  subsequent  wet  period  restarts 
growth.  If  one  varietj'  or  a  plant  does  not  show  any 
such  abnormal  growth,  it  is  regarded  as  being  more 
vigorous;  hence,  other  things  being  equal,  such  should 
be  used  for  seed,  and  all  showing  second  growth 
should  be  reje(5ted.  Abnormalities  in  shape  may  be 
due  to  contadl  with  stones  or  hard  lumps. 

13.  Trueness  to  type.  This  may  be  viewed  as  em- 
bracing several  considerations.  In  new  varieties  there 
is  always  more  or  less  tendency  to  lose  the  features  for 
which  the  variety  has  been  seledled.  The  type  is  then 
said  to  be  insufficiently  fixed,  and  often  those  which 
depart  from  the  type  degenerate.  In  such  cases  selec- 
tion must  be  continued. 

Many  varieties  are  deliberately  or  unintentionally 
.sold  for  something  else.  Mixtures  of  varieties  are 
sold  as  one.  Good  varieties  are  often  renamed  and 
sold  by  unscrupulous  seedsman  and  others  as  some- 
thing new.  There  is  considerable  duplication  of 
varieties  of  potatoes;'  thus,  Brooks,  of  Massachusetts,^ 
believes,  after  growing  the  following  varieties,  that  King 
of  the  Earliest  and  Early  Ohio,  Salzer's  Earliest  and 
Bliss  Triumph,  Mills'  Banner  and  Livingston  Banner 
are  identical,  and  that  White  Beauty  and  Cambridge 
Russet  differ  but  -slightl)-.  Mills'  Mortgage  Lifter  is 
often  sold  as  Burpee's  Extra  Early.      Some   dealers 


1  Wyo.  Bui.  32,  p.  65.  2  Hatch  (Mass.)  Sta.  Report,  1899,  p.  81. 


86  THE   POTATO 

have  been  known  to  deliberately  rename  a  well-known 
variety  and  sell  it  as  their  own,  and  as  a  new  and 
heavy  yielding  variety. 

Dakota  Red  is  sold  for  Bliss  Triumph,  although  in- 
ferior in  quality.  The  above  is  not  a  complete  list,  but 
will  show  that  this  state  of  affairs  exists,  and  empha- 
sizes the  importance  of  dealing  with  a  firm  who  have  a 
reputation  to  lose. 

Testing  Varieties. — It  is  advisable  to  secure 
copies  of  experiment-station  literature  and  papers  in 
which  variety  trials  are  reported.  The  best  variety 
for  one  soil  is  not  the  best  for  another.  The  only  way 
to  have  the  best  is  to  make  a  trial  with  small  quanti- 
ties of  different  varieties.  Secure  seven  to  ten  pounds  of 
seed  of  each  new  variety,  and  plant,  say,  three  rows  of 
each  on  a  piece  of  land  as  uniform  as  obtainable,  using 
a  standard  variety,  called  A,  as  a  check.  If  we  take 
B,  C  D,  E  as  four  untried  varieties,  buy  the  seed  in 
the  fall,  hold  it  all,  including  the  A  seed,  under  simi- 
lar conditions,  and  plant  under  similar  conditions  in  the 
following  order:  A,  B,  C,  A,  B,  E,  A.  Treat  all  plats 
alike  in  every  respect,  dig  when  ripe,  and  weigh  the 
crop.  If  the  A  plats  yield  approximately  the  same, 
then  the  dedudlion  is  that  the  soil  conditions  are  fairly 
iniiform.  If  not,  compare  the  yield  of  each  plat  with 
the  yield  of  the  A  plat  nearest  to  it.  Condu(5l  the 
trial  for  three  years.  I  find  that  the  second  and 
third  years'  results  are  better  than  the  first,  as  the 
conditions  are  more  uniform,  although  if  a  variety 
is  a  long  way  ahead  the  first  year  and  shows  up  well 
in  other  ways,  I  would  increase  the  area  under  it  at 
once. 


VARIETIES  87 

Relationship  of  Variety  to  Soil.— Disappointment 
and  loss  are  often  the  result  of  not  knowing  and  study- 
ing the  environment  best  suited  to  a  variety.  Each 
variety,  and  probably  each  individual  in  a  variety  to  a 
lesser  degree,  has  its  idiosyncrasies,  and,  to  succeed, 
these  must  be  recognized  and  catered  to.  The  failures 
in  potato-growing  deserve  more  attention.  The  suc- 
cesses take  care  of  themselves.  The  careful  grower 
takes  note  of  the  failure  and  the  success.  Both  have  a 
cause  or  causes,  and  the  climatology  and  characfter  of 
the  soil  may  be  among  them.  Some  varieties  do  better 
on  a  heavy  loam  than  on  a  sandy  loam,  probably  be- 
cause the  former  is  cooler,  owing  to  its  greater  moisture 
content,  and  under  such  conditions  these  varieties  give  a 
higher  return  of  starch  per  acre  and  are  of  better  qual- 
ity. Other  varieties,  as  those  inclined  to  be  coarse 
and  rough,  do  better  on  sandy  loams.  In  this  class  are 
Eureka  and  Uncle  Sam. 

Some  require  a  rich  loam  soil — as,  Earlj^  Ohio, 
Bovee,  Early  Harvest,  Early  Michigan.  T.  L.  Wat- 
son,' of  Virginia,  also  noted  that  some  varieties  want 
more  plant-food  than  others,  other  conditions  being 
the  same.  Others  are  more  cosmopolitan — as.  Car- 
man No.  3,  Early  Rose. 

The  Most  Popular  Varieties. — With  the  objedt 
of  ascertaining  the  best  variety  as  determined  by 
yield  in  different  places,  a  letter  was  addressed  to  the 
diredlor  of  each  experiment  station  and  to  some  grow- 
ers; 49  replies  were  received;  28  men  mentioned  vari- 
eties which  had  yielded  or  appeared  to  be  best  in  their 


1  Va.  Bill.  56,  p.  144. 


88  THE    POTATO 

districfls.  In  all  59  varieties  were  raentioued.  Tabu- 
lating the  data  presented,  we  find  that  21  of  these 
varieties  were  mentioned  twice  or  more.  In  the  South- 
ern and  Southern  Trans-Mississippi  States  all  vari- 
eties mature  about  the  same  time  and  may  be  classed 
as  earlies,  and  early  maturing  varieties  are  usually 
planted.  Of  these  and  the  early  varieties,  as  grown  in 
the  North ,  Bliss  Triumph  and  Early  Ohio  are  the  most 
popular  with  ten  votes  each;  Six  Weeks  Market  re- 
ceived five;  Early  Rose,  four  ;  Burpee's  Extra  Early 
and  Bovee,  three  each;  while  Beauty  of  Hebron,  Early 
Fortune,  Eureka,  Irish  Cobbler,  Michigan,  and  Polaris 
had  two  each.  Among  late  varieties,  Green  Mountain 
leads  with  eight  votes,  Carman  No.  3  had  five. 
Rural  New  Yorker  and  Sir  Walter  Raleigh  had  four 
each,  and  Burbank,  Carman  No.  i,  Vermont  Gold 
Coin,  Rural  New  Yorker  No.  2,  and  Freeman  had 
two  each.  Although  the  above  method  of  determi- 
nation may  not  be  absolutely  correcft,  undoubtedly  the 
varieties  mentioned  are  among  the  favorites. 

Station  Leading  Varieties 

1.  Alabama,  Tuskegee      .     Early — Bliss  Triumph. 

Medium — Early  Rose. 
Late — Peerless. 

2.  Alabama,  Auburn    .     .     Triumph. 

3.  Arizona Burpee's  Extra  Early,  Triumph, 

Early  Rose. 

4.  Arkansas Red   Bliss,  Ohio,  Michigan,  Six 

Weeks,  Crown  Jewel. 

5.  California      ....     Burbank. 

6.  Canada,  Ontario      .     .     Extra    Early  —  Pinkeye,    Stray 

Beauty,  Early  Ohio. 
Medium — Burpee's  Extra  Early, 

Rose  of  the  North. 
Late — Empire  State,    American 

Wonder. 


VARIETIES 


S/ation 
7.  Colorado  . 


8.  Connecticut 


Illinois 
Iowa  .  , 
Kansas  . 


12.  G.  L.  Foss, 

Fort  Fairfield,  Me. 


13.  Maryland  .     . 

14.  Massachusetis 


15.  Montana 


16.  Nebraska,  Bui.  80  , 

17.  New  Hampshire 

18.  New  York,  Cornell  . 

ig.  New  York,  Geneva 


Leading  Varieties 

Medium — Queen  of  the  Valley, 
Rose  Seedling. 

Late — Pearl,  Rural  No.  2. 

Late  —  Green  Mountain,  Car- 
man No.  3,  Rural  New  Yorker. 

Early — Early  Ohio. 

Vermont  Gold  Coin. 

Early — Six  Weeks. 

Medium — Early  Ohio. 

Early — Early  Ohio. 

Medium — Burpee's  Extra  Early. 

Late — Green  Mountain. 

Late — McCormick. 

Beauty  of  Hebron,  Early  Rose, 
Early  Andees,  Early  Dawn, 
Triumph,  Salzer's  Earliest, 
LX.L.,  Steuben,  Early  Nancy, 
Million  Dollar. 

Early — Si.x  Weeks  Market,  Early 
Ohio. 

Medium— White  Ohio,  Rural 
New  Yorker. 

Late — Freeman,  White  Main. 

Early — Early  Ohio. 

Late — Rural  New  Yorker. 

Late — Green  Mountain,  Wash- 
ington. 

Early — Early  Ohio-,  Bovee. 

Late — Green  Mountain^  Carman 
No.  3,  Sir  Walter  Raleigh. 

Early — Michigan,  Early  Trum- 
bull. 

Late — Carman  No.  3,  Uncle 
Sam,  Whiton's  White  Mam- 
moth, Sir  Walter  Raleigh. 


90 


THE    POTATO 


Station 
iQrt.   Prof.  Stewart, 

Geneva,  N.  Y. 


20.  Long  Island,  N.  Y. 

21.  North  Carolina 


22.  Ohio 


23.  Oklahoma  .     . 

24.  Pennsylvania 


2=;.   Rhodk  Island 


26.  Tennessee  .     . 

27.  Texas,  Bui    71 


28.  M.  Alexander, 

Charlotte,  Vt. 


29.  Washington 


Leading  Varieties 

Rural  New  Yorker  No.  2,  Car- 
man No.  3,  Green  Mountain, 
Sir  Walter  Raleigh.  (Most 
popular  late  varieties  in  the 
State,  apparently.) 

Carman  No.  i,  Green  Mountain. 

Bliss  Triumph  (both  red  and 
white  skinned),  Bovee,  Eu- 
reka, Houlton  Rose,  selected 
strains  of  Early  Rose. 

Late — Green  Mountain,  Wash- 
ington. 

Early  Ohio,  Six  Weeks. 

Medium — Bovee, Early  Fortune. 

Bliss  Triumph,  Early  Ohio. 

Early — Extra  Early  Crusaders, 
Six  Weeks,  Irish  Cobbler, 
Beauty  of  Hebron. 

Medium — J.  A..  Totten,  Free- 
man. 

Early — Early  Harvest,  Early 
Fortune,  Polaris. 

Late — New  Queen. 

Triumph. 

Triumph  (generally  grown), 
Thorburn,  Irish  Cobbler,  Eu- 
reka. 

Early — Triumph. 

Medium — Polaris,  Garfield, 
Early  Vermont,  Charles 
Downing. 

Late — Green  Mountain,  Dela- 
ware, Alexander's  Prolific, 
Dakota  Red,  Gold  Coin,  Sir 
Walter  Raleigh, Carman  No.  i, 
Carman  No.  2. 
Burbank. 


CHAPTER  VIII 
PLANTING 

Distance  Apart. — As  potato  roots  spread  laterall)- 
to  a  distance  of  2  to  2.5  feet,  the  potatoes  might  be 
planted  in  rows  four  to  fi.ve  feet  apart  without  the 
roots  overlapping  in  the  feeding-ground.  The  advan- 
tage of  such  distances  would  be  that  intertillage  could 
be  maintained  until  quite  late  in  the  season,  and  that 
there  would  be  opportunity  to  spray  the  plants  as  late 
as  one  wished.  Whether  such  distances  would  be  eco- 
nomical is  a  local  question  largely  controlled  by  the 
supply  of  moisture  available  for  the  crop.  In  Colo- 
rado the  potatoes  are  usually  planted  in  rows  four  feet 
apart.  In  humid  climates  30  to  36  inches  is  more 
common,  and  27  inches  and  even  less  is  profitable  in 
some  cases.  Other  fa(5tors  are  the  value  of  land  and 
the  cost  of  labor.  Where  land  is  low  in  value  and 
labor  high,  wdder  rows  and  the  use  of  machinery  are 
necessities.  With  high-priced  land  and  low-priced 
labor  the  rows  may  be  much  closer  together,  and  a 
much  larger  yield  per  acre  may  be  possible. 

The  most  suitable  distance  probably  varies  with  each 
variety;  it  certainly  varies  with  some.  For  spraying 
purposes  a  variety  with  long,  straggling  haulm  requires 
more  space  than  one  with  short,  upright  haulm.  Most 
of  the  early  varieties  belong  to  the  latter  tj'pe,  and  such 
are  planted  closely.  Rows  27  to  30  inches  apart,  with 
plants  8  to  12  inches  asunder,  for  early  varieties,  and 

91 


92 


THE   POTATO 


30  to  33  inches,  with  plants  12  to  18  inches  asunder,  for 
late  varieties,  are  suggested  for  most  Eastern  conditions. 
For  irrigation  experiments  in  Wisconsin,  King'  used 
30  X  15  inches  with  success.     In  Europe,  where  heavy 


-N 
^B< 

^^ 

^Pjiff^^i 

v/    *^^HHBhB^S3Bl5^H||^^^ 

Jf^^3t 

r    .^K  ^^^^^"  .  ^3^^  iSt^KK^^  ^1^^^^^^^  *  '■ 

^^l^m^: 

KIG.    23 — EARLY    MATURING    VARIETIES 

These  generally    have   dwarf    haulm,  and  may  be  planted  much  closer 

together  than  the  later  ones.     This  plant  grew  about  one  foot  tall. 

yields  are  obtained,  the  potatoes  are  planted  close  to- 
gether; thus,  Vuyst,"  of  Belgium,  and  Lavalee'  advise 
that  the  rows  be  24  inches  apart  and  the  plants  12 
inches  asunder,  because  of  the  increased  yield,  the 
hastened  maturity,  and  better-formed  tubers.  West- 
ermeier,'  of  Germany,  states  that  about  360  square 
inches  for  each  plant  gave  the  highest  yield  on  a  humous 


1  "Irrigation  and  Drainage. 
»  E.  S.  R.,  XII.,  p.  1032. 


F.  H.  King. 


2  E.  S.  R.,  v.,  p.  232. 
*  E.  S.  R.,  VII.,  p.  681. 


PLANTING  93 

loam.  This  would  result  from  rows  30  inches  apart 
with  plants  12  inches  asunder.  In  the  United  King- 
dom my  observation  is  that  2 7 -inch  rows  with  plants 
1 2  to  15  inches  asunder  for  late  varieties  and  8  to  1 2 
inches  for  early  (Fig.  23)  and  second  early  varieties  is 
most  popular.  The  Maryland  Station'  reports  25  per 
cent,  heavier  yield  from  planting  30  x  1414  inches  than 
from  36  X  1 2  inches.  The  average  of  Canadian"  exper- 
iments for  the  six  years,  1 896-1 901,  shows  that  12  to 
14  inches  asunder  in  30-inch  rows  was  better  than  10, 
16,  or  18  inches,  whether  considered  from  the  stand- 
point of  total  yield  or  of  total  jaeld  mhms  the  seed.  At 
North  Dakota  Experiment  Station,^  with  40-inch  rows 
and  the  variet}^  Early  Ohio,  it  was  better  to  plant  the 
sets  10  inches  asunder  than  at  greater  distances. 

Depth  of  Planting. — The  best  depth  varies  to 
some  extent  with  the  soil,  climate,  and  season.  It  is 
better  to  plant  deeper  on  an  open  or  light  soil  than  on 
a  compact  or  clay  soil,  in  order  to  insure  a  more  uniform 
temperature  and  moisture  supply.  These  conditions 
aid  in  the  producflion  of  good  quality  tubers.  In  a 
wet  or  a  cold  climate  shallow  planting  may  be  good 
pradlice.  In  a  wet  season,  on  a  compadl  soil,  i  inch 
or  2  inches  deep  seems  to  be  best.  The  Michigan 
Experiment  Station*  reports  that  on  a  sandy  loam,  in 
1892,  the  yields  of  potatoes  planted  at  various  depths 
were,  per  acre  :  2  inches  deep,  275  bushels  ;  3  inches, 
298  bushels  ;  4  inches,  279  bushels ;  5  inches,  273 
bushels;  6  inches,  238  bushels.     At  North  Dakota  Ex- 


'  Md.  Bui.  31,  p.  77.  =  Can.  Exp.  Farms  Report,  1901,  p.  117. 

'  N.  D.  Report,  1901,  p.  96.  *  Mich.  Bui.  95,  p.  9. 


94  THE   POTATO 

periment  Station  3  to  5  inches  deep  gave  the  heavi- 
est yields,  but  5  to  6  inches  deep  is  recommended,  as 
tubers  of  better  quality  are  produced.'  While  in  a  dry 
season,  on  a  rich  clay  loam  soil.  Green",  of  Minnesota, 
obtained  better  results  from  deep  planting,  the  yields 
being,  per  acre,  planted  on  the  surface,  216  bushels; 
3  inches,  227  bushels ;  6  inches,  297  bushels ;  8 
inches,  328  bushels,  it  was  felt  that  the  results  would 
have  been  different  if  the  season  had  been  wet.  The 
New  Jersey  Experiment  Station^  obtained  similar  re- 
sults, but  found  a  depth  of  4  inches  most '  profitable. 
From  the  data  submitted  and  other  sources,  3  inches 
to  4>^  inches  seems  to  be  the  most  profitable  depth.' 
On  soils  which  are  heavy  and  bake,  and  under  certain 
climatic  conditions,  the  seed  should  be  planted  fairly 
deep,  but  not  covered  more  than  2  inches  or  so,  to  aid 
germination.^  The  soil  can  then  be  gradually  worked 
toward  the  potatoes  until  level  culture  is  obtained. 
This  system  is  sometimes  advocated  for  the  second 
crop  in  the  South." 

Influence  of  Depth  of  Planting  on  the  Depth 
at  Which  Tubers  Form. — This  question  is  of  im- 
portance, because  mechanical  diggers  must  be  used, 
and  it  is  essential  to  know  the  depth  to  which  they 
must  work  in  order  to  dig  all  the  crop.  Zavitz,'  of 
Ontario,  as  the  result  of  three  years'  trial,  found  that 
on  an  average  potatoes  from  tubers  planted 


1  N.  D.  Report,  1901,  p.  97.  ^  Minn.  Bui.  10,  p.  74. 

3  N.  J.  Bui.  120,  p.  10,  and  Botanist's  Report,  1896,  p.  318. 

*  Ga.  Bui.  29,  p.  304.     Tex.  Bui.  71,  p.  7.        ^  Pa.  D.  A.  Report,  1902,  p.  722. 

*  Ga.  Bui.  29,  p.  305.  ''  Ont.  Agr.  Coll.  Farms  Report,  1894,  p.  98. 


PLANTING 


95 


One  inch  deep  were  formed  2.3  inches  below  the  surface  ; 
Three  inches  deep  were  formed  2.9  inches  below  the  surface; 
Five  inches  deep  were  formed  4.1  inches  below  the  surface; 
Seven  inches  deep  were  formed  6  inches  below  the  surface. 

It  was  observed  that  those  planted  i  inch  deep  fur- 
nished many  sunburned  potatoes,  while  those  planted 
deeper  had  almost  none.  Gilmore,  of  Cornell,  ob- 
tained somewhat  similar  results  during  the  year  1904. 
Goff,'  of  Wisconsin,  planted  the  Burbank  variety  at 
different  depths,  and  found  that  shallow  planting  in- 
sured greater  germination  and  more  tubers  per  hill,  but 
that  they  were  nearer  the  surface  and  had  more  ex- 
posed tubers. 

TABLE  X 


Depth 

of 

Planting 

Hills  Ger- 
minating 

Tubers 

Protrifding 

from 

Soil 

A  verage 
Number 
of  Tubers 
per  Hill 

Average 
Weight  of 

Tubers 
per  Hill 

Average 

Depth  to 

Deepest 

Tuber 

2 
4 
6 

Per  cent. 
100 
96 

88 

Per  cent. 

8.4 
.8 

6.6 

5-4 
3.2 

Pounds 

■58 
.62 
•35 

Inches 
2.5 
3-5 
50 

The  Canadian  Experiment  Farms^  report,  as  the  re- 
sult of  four  years'  trials,  that  with  tubers  planted  i 
inch  to  8  inches  deep,  where  the  sets  were  planted  less 
than  4  inches  deep,  nearly  all  the  tubers  were  formed 
between  that  depth  and  the  surface,  and  when  plant- 
ed deeper  than  4  inches  most  of  them  formed  within  4 
inches  of  the  surface.  The  deducftion  made  from  these 
results  was  that  the  potatoes  developed  in  the  surface 


1  wis.  Report,  1897,  p.  306. 


-  Can.  Exp.  Farms  Report,  1901,  p.  117. 


96  THE   POTATO 

4  inches  of  soil  because  it  was  warmer  than  the  3  or  4 
inches  lower  down. 

Influence  of  Depth  on  Quality. — On  a  sandy  loam, 
under  New  York  conditions,  potatoes  grown  about  4 
inches  deep  are  generally  of  better  quality  than  those 
grown  nearer  the  surface.  In  other  places,  those 
grown  at  even  greater  depths  have  been  observed  to 
be  of  better  quality;  thus,  at  North  Dakota  Station,' 
potatoes  5  to  6  inches  deep  were  better  than  those  3  or 
4  inches  deep  in  this  respec5l. 

Date  of  Planting. — As  would  be  expedted,  the 
dates  of  planting  potatoes  vary  widely,  and  the  only 
way  to  deal  with  the  question  is  to  give  the  common 
dates  for  a  certain  locality.  The  reader  is  advised  to 
inquire  of  the  growers  in  the  locality  the  date  con- 
sidered best,  and,  as  a  general  rule,  it  is  wise  to  plant 
early  for  the  districT;.  Canadian  experimenters'"  report, 
after  four  years'  trial,  that  the  end  of  May  is  the  best 
time,  and  that  June  24  is  usually  found  to  be  the  latest 
date  for  planting  potatoes  to  produce  satisfacftory  re- 
turns, although  in  1900  a  good  crop  was  obtained  from 
a  planting  on  July  7.  In  Wisconsin  the  middle  to  the 
end  of  May,  and  in  Maine  late  in  May  and  early  in  June, 
are  considered  best.  At  Cornell  University,  in  1901, 
potatoes  planted  May  16  yielded  250  bushels  per  acre, 
while  those  planted  June  12  and  17  yielded  162  and  197 
bushels  respedtively.  In  Oklahoma^  potatoes  planted 
March  14  came  up  and  matured  as  early  as  those 
planted  February  27.  The  early  potato  crop  of  Vir- 
ginia is  usually  planted  during  February  and  March, 


1  N.  D.  Report,  1901,  p.  96.  ^  Can.  Exp  Farm  Report,  1901,  p.  119. 

3  Okla.  Bui.  52,  p.  9. 


PI^ANTING 


97 


and  the  second  crop  about  August   i.     In  latitude  33° 
the  dates  are  about  two  weeks  later. 

Influence  of  Late  and  Early  Planting. — The 
practice  of  growing  a  late  crop  of  potatoes  has  spread 
northward,  and  in  parts  of  New  York  it  is  custom- 
ary to  plant  potatoes  late  in  the  season  after  another 
crop,  as  peas,  has  been  removed.  The  pracflice  seems 
commendable,  but  discouraging  reports  from  the  potato 
salesmen  in  regard  to  the  qualit}'  of  these  potatoes  led 
the  Cornell  University  Experiment  Station  to  under- 
take investigations  to  determine,  if  possible,  the  fa<5ts. 
Mr.  Gilmore,  who  is  conducfting  this  investigation, 
has  furnished  the  first  years'  results,  but  these  are  in- 
sufficient to  permit  of  dedudlions  being  made. 

TABLE  XI 


VARIETY 


Dale  of 
Planting 


Green  Mountain..  May  7 

Green  Mountain..  July  6 

Doe's  Pride May  7 

Doe's  Pride Jwly  6 


Date  of 
Lifting 


Sept.  1 
Oct.  22 
Oct.  20 
Oct.  22 


Total 

Ash 

Protein 

Dry 

in  Dry 

in  Dry 

Matter 

Matter 

Matter 

Per  ct. 

Per  ct. 

Per.  ct. 

22.9 

4-5 

9-77 

18. 1 

556 

11.86 

21.75 

5  39 

10-35 

19-05 

5-10 

12. II 

Starch 
i>i  Dry 
Matter 


Per  ct. 

77-38 
72-43 
74.28 
71.14 


In  both  cases  the  late-planted  potatoes  contained 
less  dry  matter  and  less  starch,  or,  in  other  words,  were 
more  watery,  and  appeared  to  be  immature.  Similar 
results  were  obtained  during  the  present  year  (1904). 

Methods  of  Planting, — The  former  method  and 
one  still  quite  common  is  to  plant  potatoes  by  hand. 
A  furrow  is  thrown  out  by  a  common  plow,  or  a 
shovel-plow,  5ind,  if  applied,    the   fertilizers,    and    in 


PLANTING 


99 


some  cases  the  manure,  are  placed  in  the  furrow,  the 
potatoes  dropped  in,  and  then  covered  by  the  plow. 
Generally  speaking,  the  furrows  should  be  thrown  out 
so  that  the  potatoes  will  be  four  inches  below  ground 
when  the  surface  is  level.     The  furrows  are  made  the 


B 


Courtesy  Cornell  University, 

FIG.  25 — PLANTING    BY    HAND 

A — Tuber  planted  by  hand  in  furrow  opened  with  a  shovel  or  double  mold- 
board  plow.  B — The  potatoe.s  covered  with  shovel  plow.  C— l,and  har- 
rowed level  a  few  days  after  planting,  to  destroy  weeds,  leaving  the 
potatoes  four  to  five  inches  deep.  Few  farmers  plant  at  this  depth,  even 
when  they  mean  to  do  so. 


required  distance  apart.  It  has  been  deemed  necessary 
to  place  the  potato  in  position,  and  fix  it  so  that  it  will 
not  move  when  covered.  In  England  this  is  done  by 
requiring  the  planters  to  press  it  down  by  hand,  and 
in  this  country  the  potatoes  are  often  stepped  on  for 
the  same  reason.     The  stepping  on  them   may   injure 


lOO 


THK   POTATO 


buds,  and  hence  is  detrimental.  The  rows  should  be 
made  straight,  and  care  should  always  be  taken  to 
have  the  potatoes  planted  in  a  straight  line  and  at  a 
uniform  distance  apart.  The  former  facilitates  in- 
tertillage  to  such  an  extent  that  it  is  worth**'  of  atten- 
tion.    On  a  dry,  hot  day  it  is  inadvisable  to  open  the 


FIG.   26 — SECTIONAL    VIEW    (il"    ASI'INWALL    I'LANTER 


rows  much  ahead  of  the  planters,  and  the"  seed  should 
be  covered  as  soon  as  possible  to  prevent  loss  of  mois- 
ture. Frequently  the  rows  plowed  out  before  the  noon 
meal  hour  and  left  ojien  for  this  time  show  the  injuri- 
ous effedl  of  the  loss  of  moisture,  especiall}^  if  the  seed 
is  cut.  Wherever  hand-planting  is  done  and  the 
tubers  are  not  sprouted,  the  hand-planters,  which  are 


PLANTING 


lOI 


somewhat  like  hand  corn-planters,  may  be  used  with 
profit.  They  cost  $i  .00  to  $1 .50,  and  it  is  claimed  that 
an  adlive  man  can  plant  at  least  one  acre  per  day. 

Every  large  grower  of  potatoes  requires  a  horse- 
planter.  From  six  to  eight  acres  will  warrant  the 
use  of  such  a  machine,  and  it  may  be  made  to  pay  for 
itself  in  a  short  time  by  hiring  it  out — preferably  with 


FIG.   27 — ASPINWALL    POTATO    PLANTER    (SIUE    VIEW) 


a  man  to  work  it.  Some  planters  require  one  man, 
others  two  men,  to  work  them;  the  latter  generally 
do  the  best  work,  although  good  work  is  done  by  the 
former.  Two  systems  of  mechanism  are  employed — the 
picker  and  the  platform.  In  some  planters  the  tubers 
are  fed  from  the  hopper  onto  pickers,  or  spikes,  which 
projecft  from  a  revolving  vertical  disk.  The  disk 
carries  them  round  to  the  top  of  a  delivery  pipe,  where 
they  are  knocked  off,  or  fall  off,  going  down  the  pipe 


I02 


THE    POTATO 


to  the  ground.  This  system,  or  a  modification  of  it,  is 
used  in  the  Aspinwall  (Figs.  26-27),  the  Deere,  and  the 
the  Eureka  planters.  Trials  with  a  planter  of  this  type 
showed  that,  with  small  whole  seed  and  well-prepared 
ground,  this  machine  will  work  up  to  its  guarantee  of 
95  per  cent. ;  that  is,  it  will  not  skip  more  than  5  places 
in  100.     With  longer  cut  seed  and  rougher  land,  espe- 


FIG.   28 — THE    ROUHI.NS    IMPROVED    PLANTER 


cially  if  slightly  hilly,  it  will  miss  up  to  20  in  100.  If 
these  misses  were  distributed  it  would  not  be  so  serious, 
but  often  5  or  6  occur  at  a  .stretch.  If  the  seed  is  cut 
long  and  thin,  the  pickers  ma}'  take  hold  of  two  pieces 
instead  of  one.  This  happens  frequently — often  up  to 
20  per  cent.  These  machines  open  the  furrow,  distribute 
the  fertillizer,  plant  the  potato,  and  cover.  The  latter 
operation  is  usually  performed  by  revolving  concave 
disks.  The  distance  apart  of  the  tubers  is  regulated  by 
adding  or  removing  the  pickers.     The  higher-priced 


PLANTING  103 

machines   are   stronger  made  than  the   lower-priced, 
and,  in  some  cases  the  fertiHzer  attachment  is  extra. 

The  Robbins  improved  potato-planter  (Fig.  28)  is  of 
the  platform  type.  The  potatoes  are  elevated  from  the 
hopper  by  means  of  a  wheel,  and  are  discharged  onto  a 
platform  which  is  cleared  by  several  revolving  arms 
(Fig.  29);    the  mechanism  is  so  timed  that  a  potato 


FIG.  29 — THE    I'LATFOKM    OF    THE    ROBBINS    IMPROVED    PLANTER 

should  fall  on  the  platform  between  each  two  arms. 
Sometimes  the  elevator  comes  up  empty  or  brings  two 
pieces  up  ;  in  either  case  it  is  necessary  for  the  man  sit- 
ting behind  to  put  one  piece  on  the  vacant  part  of  the 
table  between  the  arms  or  take  the  extra  piece  off.  In 
this  way  the  tubers  are  planted  more  carefully  and  regu- 
larly than  most  hand  work.  The  amount  and  distance 
apart  of  seed,  and  the  amount  of  fertilizer  sown,  are 


I04  THE    POTATO 

regulated  by  interchangeable  sprockets.  The  various 
parts  of  the  machine  are  driven  by  means  of  a  chain 
drive.  This  machine  opens  the  row,  distributes  the 
fertilizer  in  rather  a  wide  stream,  plants  the  potato, 
and  covers  it  in  a  satisfa(5lory  manner.  Any  ordinary 
required  depth  can  be  obtained.  It  can  be  used  for 
planting  beans,  corn,  and  other  crops.  With  potato- 
planters  three  to  six  acres  can  be  planted  per  da3\ 

Losses  of  crop  due  to  insufficient  seeding  cannot  be 
made  up  during  the  year.  The  land  requires  the  same 
amount  of  work,  and  the  soil  needs  moving  at  digging- 
time;  but  there  is  not  the  yield,  and  it  is  an  important 
consideration  whether  5  per  cent,  to  20  per  cent,  los;; 
of  plants  per  acre  is  not  too  high  a  price  for  the  sake  o. 
one  man's  pay  per  day.  Even  with  the  cheapest 
"  picker ' '  planter,  the  lower  initial  cost  is  not  sufficient 
to  recompense  the  grower  for  the  lo.ss  sustained  by 
using  it  on  ten  acres  when  compared  with  the  perfedl 
machine. 


CHAPTER  IX 
MANAGEMENT   OF    THE    GROWING    CROP 

Cultivation. — Almost  invariably  judicious  cultiva- 
tion of  potato  land  is  profitable.  It  is  secondary  to 
good  preparation  of  the  land.  The  objedl  is  not 
primarily  to  destroy  weeds,  although  this  may  be  a 
consideration.  To-day  intelligent  farmers  till  to  in- 
crease yield.  Tillage  is  manuring.  No  better  illustra- 
tions of  this  fadl  can  be  found  than  the  tillage  experi- 
ments of  Roberts  and  others  at  Cornell  University.'  In 
these  trials  potatoes  were  grown  several  years  in  suc- 
cession, without  manures  or  fertilizers,  upon  the  same 
land,  and  yields  varying  from  300  to  350  bushels  per 
acre,  or  three  to  four  times  the  average  jdeld  of  the 
State,  were  secured  for  several  years.  This  illustrates 
the  value  of  tillage,  but  in  its  entirety  is  not  necessarily 
a  good  pradlice.  Tillage  destroys  humus,  and  as  this 
is  one  of  the  most  essential  constituents  of  a  good 
potato  soil,  a  rotation  of  crops  is  advised  to  aid  in 
maintaining  the  supply.  Tillage  may  be  overdone, 
especially  deep  tillage  in  dry  weather.  During  such  a 
time  only  sufficient  shallow  tillage  should  be  given  to 
maintain  a  mulch. 

At  Cornell  from  seven  to  nine  cultivations  seemed  to 
be  most  profitable,  or  about  every  seven  to  ten  days  until 
the  potato-vines  meet  in  the  rows.  Tillage  must  be 
given  when  necessary.      The  right  number  of  cultiva- 


'  (N.  Y.)  Cornell  Bui.  140,  pp.  389-390;  191.  P-  192. 

105 


Io6  THE   POTATO 

tions  will  vaty  with  each  year  and  the  class  of  soil. 
The  Ohio  Kxperiment  Station'  found  that  thorough 
culture   encouraged   vigorous   growth   and   aided  the 
plants  to  resist  fungous  troubles. 
The  objedls  of  tillage,  then,  are  : 

1.  To  increase  the  crop-producing  power,  presum- 
ably by  : 

(a)  Liberating  plant-food. 

(d)  Maintaining  good  texture. 

(c)  Conserving  moisture  by  the  aid  of  a  soil  mulch. 

(d)-  Pulverizing  the  ground,  so  that  every  shower 
of  rain  can  enter  the  soil  and  not  flow  off, 
transporting  the  fine  soil  particles. 

2.  To  keep  weeds  in  check. 

System  of  Culture.— ^///^.— Generally  hills— that 
is,  where  potatoes  are  planted  in  checks — are  unprofit- 
able because  there  are  not  enough  plants  per  acre  and 
the  yield  is  too  low;  hence  the  system  is  little  used  un- 
less a  piece  of  land  is  very  weedy. 

Drills. — By  "  drills"  it  is  understood  that  the  soil  is 
thrown  toward  the  potatoes,  leaving  a  depression  or 
furrow  between  the  rows.  This  system  is  used  for 
irrigation,  when  the  water  flows  between  the  rows.  It 
is  also  pradliced  in  humid  climates,  where  the  tempera- 
ture does  not  go  high — as.  Northern  England,  Scot- 
land, etc. — and  on  wet  soils  and  in  wet  seasons.  Often 
the  "furrowing"  injures  roots  and  reduces  the  yield, 
but  many  growers  claim  that  the  ease  with  which  the 
potatoes  can  be  dug  from  drills  compensates  for  any 
loss  in  yield.     The  objedlion  to  level  culture  is  that 


Ohio  Bui.  76,  p.  47.  LIBRARY. 

Didsion  of  Horticulture, 

N.  C.  Dep't  of  Amodture* 


MANAGEMENT   OF   THE   GROWING   CROP 


107 


difficulty  is  experienced  in  securing  machinery  which 
will  dig  all  the  tubers. 

Level  Culture.  —  In  this  system  the  potatoes  must  be 
planted  a  little  deeper  than  in  the  case  of  the  other 
two,  to  reduce  the  percentage  of  sun-burned  tubers. 
This  system  is  advocated  throughout  most  of  Eastern 
North  America,  as,  among  other  things,  the  quality  of 


FIG.    30 — HALI.ECK    EXPANSIBI.E    WEFDER 


the  potatoes  is  better,  owing  to  the  ground  being 
cooler.  Its  use  has  been  found  advisable  at  such 
various  points  as  Cornell,'  Louisiana,"  North  Caro- 
lina,^ Wisconsin,'  and  Arkansas''  Experiment  Stations, 
while  the  Maryland'  Station,  in  a  trial  lasting  six  years, 
found  little  difference  between  level  and  drill  culture, 
but  the  slight  variation  was  in  favor  of  level  culture.  " 
Method  of  Cultivation  and  Tools  Used. — About 
a  week  after  planting  the  spike-tooth  harrow  should 
be  run  over  the  land,  preferably  in  both  directions,  if 
a  mulch  is  not  made  by  one  harrowing.     This  destroys 


•  (N.  Y.)  Cornell  Bui.  140,  p.  390;  156,  p.  175. 
3  N.   Car.  Bui.  85,  p.  4;  146,  p.  262. 
'  Ark.  Bui.  50,  p.  29. 


-  I,a.  Bui.  22,  p.  705. 

*  Wis.  Report,  1899,  p.  210. 

*  Md.  Bui.  62,  p.  204. 


Io8  THE    POTATO 

young  weeds  and  brings  more  seed  up  to  germinate, 
which  ma}'  be  killed  by  another  harrowing  a  week 
later.  When  the  potatoes  appear,  the  weeder  (Fig.  30) 
will  be  found  the  most  serviceable  implement  for  holding 
the  weeds  in  check  and  maintaining  the  mulch.     It  may 


FIG.    31  —  FIVK-TOOTIt    CULTIVATOR    WITH    lULLEK    ATTACHMENTS 
Still  used  by  many  farmers. 

be  driven  across  the  rows  after  each  cultivation  until 
the  potatoes  are  9  or  10  inches  high.  As  a  good 
horse  and  man  can  do  twenty  acres  a  day,  it  is  quite 
expeditious  and  generally  satisfaclor}-. 

Generally  speaking,  it  is  advised  to  cultivate  widely 
and  deeply  from  4  to  6  inches  the  first,  and,  in 
some  cases,  the  .second  time  after  the  potatoes  aj'pear, 
then  reduce  the  width  and  the  depth  to  one  inch  or  so. 


MANAGEMENT    OF    THE    GROWING    CROP  IO9 

The  first  and  second  cultivations  may  be  given  with  a 
five- tooth  cultivator  (Fig.  31),  or  a  sulky  cultivator 
(Fig.  32)  maybe  used.  The  spring-tooth  cultivator 
(Fig.  33)  is  found  to  be  a  very  useful  tool  for  inter- 


FiG.  32 — A  USF.KIL    r\v>.)-in>RSK  rri,ii\AroR 
A  requisite  wherever  large  areas  of  potatoes  are  grown. 

tillage  work  for  the  third  and  subsequent  cultivations, 
and  the  spike-tooth  expansible  cultivator  with  the 
shields  is  an  excellent  tool  for  shallow  tillage,  as  it 
destroys  the  small  weeds  and  helps  to  maintain  a  soil 
mulch. 


no 


THE   POTATO 


Mulching. — In  some  districSls  good  yields  have 
been  obtained  by  mulching  the  land  with  straw, 
shavings,  pine  straw,  or  some  similar  substance,  instead 
of  cultivating  it.     Waugh  found  that  it  increased  the 


FIG.    33  —  iiNK-HoKsl      ^  I   Kl  N(,- I  OOTH    CUL'llVATOR 
An  excellent  tool  for  the  later  cultivations. 

yield  in  Oklahoma'  and  similar  results  were  obtained 
in  New  Jersey,^  while  in  Georgia,^  Michigan,^  Wis- 
consin,^ and  in  my  own  trials  in  New  York,  it  was 
found  to  be  unprofitable,  even  when  the  yields  obtained 
were  about  the  same  under  both  conditions. 


'  Okla.  Bui.  15,  p.  32. 

3  Ga.  Bui.  29,  p.  348. 

*  Wis.  Report,  1899,  p.  209. 


2  N.  J.  Report,  1901,  p.  418. 
*  Mich.  Bui-  95,  pp.  13-16. 


CHAPTER  X 

OBSTRUCTIONS  TO   GROWTH   AND 
DEVELOPMENT 

The  obstrudlions  to  growth  may  be  treated  under 
the  following  heads: 

1.  Season  a7id  Climate. 

2.  Weeds. 

3.  Diseases  due  to  parasitic  fiaigi  and  bacteria. 

4.  Insects. 

5.  Arseyiical  poisoning. 

I.  Influence  of  Season  and  Climate. — The  in- 
jurious influence  of  dry  weather  at  planting-time  has 
already  been  observed  ("Viabilit}-,"  page  66).  At 
the  (Hatch)'  Massachusetts  Experiment  Station  it  was 
observed  that  the  wet  condition  of  the  soil  at  the  time 
of  planting  appeared  to  induce  the  rotting  of  the  young 
plants  just  below  ground.  The  occurrence  of  several 
extremely  hot  sunny  days  in  July,  following  a  long 
rainy  period,  caused  the  plants  to  wilt  from  the  wet 
condition  of  the  soil  and  low  vitality.  No  disease  was 
apparent.  Probably  these  plants  showed  the  injurious 
results  consequent  on  defedlive  respiration  due  to  high 
temperatures.  Frost  may  cut  down  early  planted 
potatoes. 

Tip  Bnrn.'' — This  is  most  common  in  Northeastern 


1  Mass.  (Hatch)  Report,  189S,  p.  52. 

2  Ver.  Report,  1899,  p   151;  Bui.  72,  p.  10.    (N.  Y.)  Cornell  Bui.  113,  p,  309. 
Conn.  Report  18  (1894),  p.  133. 


Ill 


112  THE   POTATO 

America.  The  leaves  become  brown  on  the  margin 
and  die.  It  is  caused  by  drought,  and  is  more  prevalent 
on  light  soils.  Irrigation  and  seledlion  of  vigorous 
varieties,  more  care  in  cultivation,  and  fertilizing  are 
suggested.  At  Wisconsin  Experiment  Station,'  Green 
Mountain,  Rural  New  Yorker  No.  2,  Everett's  Heavy 
Weight,  and  Colossal  proved  most  resistant  in  1896. 

Siin  Scald.'' — Its  efFedl  is  similar  to  that  of  tip  burn. 
It  is  more  prevalent  in  the  Southeastern  United  States, 
and  is  often  noticed  when  long-continued  damp  weather 
is  followed  by  several  hot,  bright  days. 

2.  Weeds. — These  injure  the  plant  by  using  water 
and  other  plant-food,  crowding  the  plant,  preventing 
the  free  circulation  of  air,  and  in  these  ways  reducing 
the  vitalit}'  and  rendering  the  potato  more  subjedl  to 
disease. 

3.  Diseases  Due  to  Parasitic  Fungi  and  Bacte- 
ria.— Late  Blight  or  Rot  '  {Phytophthora  infestans). 
— There  is  reason  to  believe  that  this  di.sease  has  existed 
for  ages  in  the  western  parts  of  South  America,  and 
was  disseminated  over  Europe  a  long  time  before 
its  presence  was  recognized.  It  seriously  injured  the 
crops  of  potatoes  in  the  United  States  and  Canada 
in  1843,  and  reappeared  the  following  year.  In  July, 
1845,  it  was  first  detecfted  in  Europe,  in  Belgium,  and 
within  two  months  thereafter  it  was  recorded  in  Eng- 
land, Ireland,  Scotland,  France,  Germany,  Denmark, 
and  Russia.     Since  that  time  it  has  never  been  entirely 


1  Wis.  Report,  1896,  p.  240.  -  U.  .S.  D.  A.  Farmers'  Bui.  91,  p. 

*  (N.  Y.)  Cornell  Bui.  113,  pp.  297-302.     Vt.  Bui.  49,  pp.  90,  91;  Bui 
13.    U.  S.  D  A.  Farmers'  Bui.  91,  p.  8. 


OBSTRUCTIONS  TO   DEVELOPMENT  II3 

absent  from  the  potato  crops,  although  in  some  years 
it  is  not  so  destrucftive  as  in  others. 

The  disease  appears  during  damp,  muggy  weather  in 
August  and  September.  It  is  often  noticed  as  small 
brownish  spots  on  the  lower  leaves,  which  rapidly  en- 
large. In  moist  weather  the  edges  of  these  spots, 
on  the  under  surface  of  the  leaf,  appear  to  be  covered 
with  a  white  downy  mildew.  In  dry  weather  this 
may  be  difficult  to  detecft.  L,ater  the  leaves  appear 
as  though  burnt,  and  finally  the  whole  plant,  and 
in  some  cases  the  whole  field,  will  become  a  putrid, 
offensive  mass  of  decaying  stems  and  leaves.  The 
tubers  may  be  attacked  also,  and  rot  in  the  field  or 
in  storage.  Sometimes  the  disease  runs  a  very  rapid 
course,  and  a  field  will  wilt  down  in  twenty-four 
to  forty-eight  hours. 

Ca2(se. — The  cause  is  a  parasitic  fungus  which  com- 
pletes its  life  history  in  four  or  five  days  or  less.  The 
whitish  mold  is  made  up  of  stalks  bearing  branches 
(Fig.  34).  These  bear  spore  cases  (Figs.  34  and  35), 
which  break  up  to  form  spores  (Fig.  35).  These 
spores  send  out  small  tubes  (Figs.  35,  36,  37),  which 
enter  the  potato  leaf  through  a  stomata,  or  breathing 
pore  (Fig.  37),  or  penetrate  the  cell  wall  (Figs.  36,  37). 
The  tubes  spread  in  the  walls  of  the  leaf  cells  (Fig. 
34)  like  mushroom  spawn  in  a  mushroom  bed,  utiliz- 
ing the  plant-food  which  should  go  to  form  tubers. 
At  intervals  they  send  out  spore-bearing  branches 
through  the  stomata  (Fig.  34),  which  perpetuate  the 
trouble.  Unless  the  tubers  are  well  covered  with  soil, 
the  spores  may  fall  on  the  ground,  and,  reaching  the 
tubers,  transmit  the  disease  to  them. 


114 


THE   POTATO 


FIG.    34 — SECTION    OF    A    POTATO    LEAK 
(After  Marshall  Ward) 

Showing  the  parts  and  the  threads,  or  mycelium,  of  the  blight  or  rot  {Phy- 
lophlliura  itifcslaus)  a — Epidermis,  or  outer  cells,  b — Palisade  cells,  which 
aid  in  giving  rigidity-  and  firmness  to  the  leaf,  and  in  the  manufacture  of 
starch  and  other  ingredients,  c — Spongy  tissue,  showing  cells  and  large 
air  spaces  between,  d — The  stoniata,  or  breathing  pores  of  the  leaf,  with 
aerial  branches  of  the  parasite  growing  outward  through  them,  e — The 
spore  sacs,  or  conidia,  in  which  the  spores,  or  seeds,  are  formed.  /^\  pe- 
culiar hair  on  the  under  surface  of  the  leaf.  The  dots  in  the  cells  are  the 
chlorophyll  granules,  which  give  the  green  color  to  the  leaf,  and  aid  in  the 
production  of  starch.  The  dark  parts  of  the  tis.sue  show  where  cells  are 
dying  from  the  effects  of  the  disease.  Loss  of  cells  means  a  reduction  in 
the  amount  of  food  prepared,  and,  consequently,  reduced  yield.  In  New 
York  alone  the  farmers  lose  js, 000,000  to  f  10,000,000  annually  from  diseases, 
and  because  they  do  not  spray.  This  is  the  most  important  disease  preva- 
lent at  present. 


Aids  to  Attack. — i.  Flea-beetles  puncfture  the  leaves 
and  furnish  easy  access  for  the  spores  to  the  inner 
parts  of  the  leaf. 

2.  Humid,  still  days,  with  a  tempera't-ure  of  about  73° 


OBSTRUCTIONS   TO   DEVELOPMENT 


115 


F.     Above  78°  F.  and  below  50°  F.  there  is  pracftically 
no  germination  of  the  spores. 

Prevention. — i.  Spraying  with  copper  compounds — 
as,  Bordeaux  mixture,  copper  sulphate  and  soda  mix- 


FIG.   35 — THE     MATURA'ION     OK     A     SPORE     SAC     (CONIDIA)     AND 

GERMINATION     OF    A    SPORE    (ZOOSPORE)    OF     ROT 

{Pkytop/Ukora    i lifts tatis) 

(After  Marshall  Ward) 

a — Ripe  spore  sac  in  water,     b — The  protoplasmic  contents  break  up  into 

blocks  and  escape  as  kidney-shaped  zoospores  (c  and  d).    e — Each  have 

two  thread-like  arms,  called  cilia,  which  are  lost  as  the  spore  comes  to  rest 

(/and  g)  ;  /;,  i,j\  and  k  show  stages  of  germination.     Moist,  warm,  or  still, 

muggy  days  are  best  for  the  growth  and  development  of  these  spores.     On 

such  occasions  the  disease  spreads  rapidly. 


ture.  If  the  surfaces  of  the  leaves  and  stems  be  covered 
with  a  thin  film  of  some  copper  compound,  we  either 
prevent  the  entrance  or  injure  the  vitality  of  the  ger- 
minating .spore  tubes,  so  that  the  potatoes  enjoy  a 
certain  degree  of  immunity  from  the  disease. 

This  is  the  philosophy  of  the  use  of  Bordeaux   mix- 


ii6 


THE   POTATO 


ture.  The  degree  of  immunity 
varies  with  our  ability  to  keep 
the  whole  of  the  plant  covered 
with  an  armor  of  Bordeaux 
mixture.  Plants  half  sprayed 
are  not  secure,  as  the  disease 
can  spread  rapidly  inside  the 
plant.  The  plant  must  be  com- 
pletely coated  all  the  time  to  be 
immune.  This  may  be  impos- 
sible when  a  plant  is  growing, 
but  this  is  not  the  fault  of  the 
Bordeaux  mixture.  The  more 
thoroughly  and  more  frequently 
the  spraying  is  done  the  better 
the  chances  of  bringing  the 
crop  through.  It  will  be  seen 
that  Bordeaux  is  but  a  prevent- 
ive; it  is  not  a  cure.  Hence, 
the  poof  results  from  spraying 
after  the  disease  has  obtained  a 
foothold. 

2.  Obtaining  disease-resisting 
varieties,  or  changing  the  seed 
if  it  has  lost  its  resisting  power. 

3.  Planting  on  fresh  ground, 
and  planting  early. 

4.  Giving  good  cultivation, 
and  having  a  good  rotation. 

5.  Destroying  all  refuse  of 
potatoes. 

6.  Having  good  drainage — both  water  and  air  drain 


FIG.  36 — LONGITUDINAL 
SECTION  OF  A  POTATO 
STALK,  SHOWING  A  GER- 
MINATING SPORE  OF  ROT 

{P/ivtop/itkora  infestans) 
(After  Marshall  Ward) 

The  number  of  stomata.per 
square  inch  on  a  potato  stem 
is  much  smaller  than  in  the 
case  of  a  leaf,  but  here  the 
germ  tube  has  pierced  the 
cell  wall,  and  is  growing  in 
the  cell.  In  spraying,  the 
stems  should  be  coated  with 
Bordeaux. 


OBSTRUCTIONS  TO    DEVELOPMENT 


117 


age.  Near  woodland,  where  the  air  drainage  is  poor, 
the  disease  spreads  rapidly  on  damp  or  misty  days. 
Land  choked  with  weeds  keeps  the  lower  leaves  and 
stalks  damp,  and  more  subject  to  attack. 


FIG.   36 — THE    GERMINATING    TUBE    OF    A    SPORE    OF    ROT 

{^Phytophthora  infestans) 
(After  Marshall  Ward) 
This  may  enter  a  plant  through  a  stomata,  or  breathing  pore,  as  at  a,  or 
it  may  penetrate  the  cell  wall,  as  at  b.     The  maintenance  of  a  coat  of  Bor- 
deaux mixture  all  over  the  plant  would  check  the  growth  of  these  spores. 


7.  Not  digging  until  ten  days  after  the  vines  die. 

8.  Getting  potatoes  out  of  the  field  as  soon  as  dug, 
and  never  covering  piles  of  potatoes  with  spore-laden 
haulm. 


I  I  8  THE    POTATO 

Early  Blight,'  or  Leaf  Spot  Disease  {Macro- 
spon'jwi  so/afiz). — It  is  a  fungus  disease  which  appears 
usually  in  June  to  July,  or  ahead  of  the  late  blight.  It 
does  not  generally  attack  vigorous  plants.  It  spreads 
in  warmer,  drier  weather  than  the  late  blight.  It  forms 
circular  brown  spots  with  target-like  markings  on 
the  leaves.  It  enters  the  leaf  through  tissues  weak- 
ened by  other  agents,  as  flea-beetles,  etc.  It  does  not 
attack  the  tubers  directly,  and  never  causes  them  to  rot. 

Preventives. — i.  Spraying  with  Bordeaux  mixture. 

2.  Seledlion  of  vigorous  varieties. 

3.  Better  tillage  and  fertilization. 

Potato  Rosette  {RJdzoctonia  solani.") — This  dis- 
ease has  been  known  since  1842,  but  it  is  only  recently 
that  it  has  caused  considerable  trouble.  It  is  now  well 
established  all  over  the  country,  and  in  some  places  90 
per  cent,  of  the  tubers  appear  to  be  affecled  by  it.  It 
tends  to  cau.se  the  formation  of  an  abnormal  number  of 
small  tubers  of  no  value.  The  stems  show  discolored 
deca3'ing  areas  above  ground  and  brown  dead  areas  be- 
low, and  the  leaves  tend  to  grow  in  rosette-like  clusters. 
The  resting  spores  live  for  several  years  in  the  .soil,  and 
the  methods  of  infedlion  are  by  seed  potatoes,  beet  and 
mangold  roots,  dead  potato  stems,  and  some  weeds; 
hence,  fields  .should  be  kept  clean.  The  disease  at- 
tacks beets,  mangolds,  and  clover.  Soaking  the  seed 
in  formalin  will  destroy  the  spores  on  the  potatoes,  but 
is  of  no  value  if  the  soil  is  infe<fted.      Planting   sound 


1  Vt.  Bui.  49,  pp.  91-96;  Bui.  72,  pp  16-25.  U.  S.  D.  A.  Farmers'  Bui.  15,  pp. 
4,  5;  Bui.  91,  p.  5.  (N.  Y.)  Geneva  Bui.  123,  p.  236.  N.  H.  Bui.  45,  pp.  50,  56. 
Tex.  Bui.  42,  p.  923. 

•^  (N.  Y.)  Cornell  and  Geneva  Bui.  186.   Col.  Bui.  69,  70.   Ohio  Bui.  139,  145. 


OBSTRUCTIONS   TO    DKVELOPMKNT  I IQ 

tubers  and  a  good  rotation  of  crops  will  aid  in  com- 
batting the  trouble. 

Scab  {Oopsora  scabies  Than.). — Thaxter  has  shown 
that  this  fungus  is  the  chief  cause  of  scab  (Fig.  38), 
although  Roze  claims  that  the  primarj^  cause  is  bacte- 
rial, and  that  the  fungus  Oospora  scabies  and  other 
organisms  follow,  causing  the  familiar  rough  and 
cankerous  appearance  of  scab.  Other  causes  are  also 
given.'  .  An  enormous  amount  of  work  has  been  ex- 
pended on  this  disea.se,  and  still  no  absolute  preventive 
is  known  if  the  land  is  inoculated  with  the  trouble. 

Treatment . — Of  a  large  number  of  substances  used 
for  treating  the  seed  potatoes,  soaking  them  in  a  solu- 
tion of  formalin,  i  pound  to  30  gallons  of  water,  for  2 
hours  is  the  most  effedtive.  Soak  the  potatoes  before 
cutting  them,  and  if  they  are  not  planted  at  once 
spread  them  thinly  to  dry.  If  left  in  bags  they  will 
heat  and  the  buds  be  ruined.  After  soaking  two  or  three 
lots  of  potatoes  the  .solution  should  be  changed,  as  it 
loses  its  efficacy.  A  big  cheese-vat  or  sheep-dipping 
vat,  in  which  .several  bags  may  be  placed  at  a  time,  is 
useful.  A  small  block  and  tackle  will  enable  one  man 
to  lift  large  bags  in  and  out  of  the  vat,  and  suspend 
them  to  permit  of  some  drainage. 

The  following  points  are  of  importance. 

An  acid  condition  of  the  soil  is  injurious  to  the 
growth  of  scab.  Lime,  wood  ashes,  and  barn  manure 
aid  the  growth  of  scab,  while  sulphate  of  ammonia, 
muriate  of  pota.sh,  sulphate  of  potash,  kainit,  acid  phos- 
phate, and  dissolved  bone  render  the  soil  less  favorable 


1  W.  Va.  Special  Bui.  44,  pp.  2S5-6. 


OBSTRUCTIONS   TO    DEVEI.OPMENT  121 

to  the  disease.  Scabby  seed  will  inoculate  clean  land. 
Scabby  potatoes  cannot  be  sold.  If  used  as  fertilizer, 
even  after  steaming  for  twenty  minutes^  or  being  ex- 
posed to  the  weather  all  winter,  they  will  inoculate  the 
land  they  are  spread  on. 

Exposing  tubers  to  sunlight  for  four  weeks  before 
planting  reduces  the  percentage  of  scab  and  hastens 
growth. 

Scab  can  live  in  the  soil  at  least  six  years  without  a 
known  host.  Beets,  mangolds,  turnips,  and  rutabagas 
are  subjecft  to  the  same  disease;  hence  in  the  rotation 
these  crops  should  be  avoided,  if  possible. 

Varieties  vary  in  their  susceptibility  to  scab,^  the 
thicker  skinned  varieties  being  reported  as  most  re- 
sistant. 

It  seems  to  be  useless  to  treat  scabby  seed  if  they  are 
to  be  planted  on  scab-infested  land.^ 

Plowing  under  green  rye  does  not  diminish  scab,  as 
has  been  stated.' 

Applying  sulphur  in  the  rows  at  the  rate  of  300 
pounds  per  acre  and  more  has  been  tried  extensively, 
but  is  not  recommended  as  a  practice,  as  it  is  of  little 
use  on  infested  land. 

Diseases  in  Storage. — Wet  Rot  has  several 
causes. 

I.  Blight  or  Rot  {Phytophthora  infestans).  The 
tissues  of  the  tuber  become  soft  either  partially  or 
wholly,  the  skin  shrinks,  and  the  layer  under  it  be- 
comes pasty.     Potatoes  from  light  soils  appear  to  be 


N.  J.  Report,  1899,  pp.  344-345..       2  ]\j.  j   Report,  1899,  p.  329;  1900,  p.  417. 

(N.  Y.)  Geneva  Bui.  138,  p.  631. 

(N.  Y  )  Geneva  Bui.  138,  p.  629.    N.  J.  Report,  1900,  p.  417. 


122  THE    POTATO 

less  subjecft  to  it  than  those  from  heavy  soils,  and  the 
disease  spreads  most  rapidlj^  in  a  damp,  warm,  and 
close  cellar. 

2.  Due  to  badleria.'  The  tubers  may  be  wholly  or 
partially  soft,  and  exhale  a  disagreeable  odor.  Butyric 
acid  may  be  liberated  and  the  destru(flion  of  the  tubers 
is  slow.    ContacT:  with  other  potatoes  should  be  avoided. 

If  to  be  used  for  seed,  in  some  cases  depending  on 
the  cause,  soaking  the  tubers  in  formalin  before  plant- 
ing is  beneficial. 

Dry  Rot  may  be  the  evidence  of  the  presence  of  one 
or  more  of  several  troubles." 

1.  Stem  rot,'  bundle  blackening,  dry  end  rot,  is  be- 
lieved to  be  due  to  a  fungus  {Fusariuj?i  oxysporuni); 
the  leaves  curl,  and  the  foliage  wilts  and  dies.  The 
tubers  show  brown  or  blackened  bundles  at  the  stem 
end  under  an  apparently  sound  skin.  The  disease 
spreads  rapidly  in  storage,  especially  if  the  rooms  are 
warm.  Some  investigators  advise  that  diseased  tubers 
should  not  be  fed  to  stock,  thrown  on  the  manure-pile, 
or  planted,  and  that  all  such  potatoes  should  be  de- 
stroyed at  harvest-time  or  as  soon  as  discovered.  No 
remedy  is  known. 

2.  Due  to  badleria.  The  tubers  may  be  free  from 
odor,  moderately  firm,  but  more  or  less  soft  in  spots, 
showing  in  places  a  loose  skin,  which  yields  to  the  fin- 
ger, and  under  which  are  white,  gray,  or  brownish 
blotches.  Soaking  unafFedled  tubers  in  formalin  before 
planting  is  suggested. 


•  111.  Bui.  40,  p.  140.  2  111.  Bui.  40,  p.  139.     Tex.  Bui.  42,  p.  926. 

=>  U.  S.  D.  A.  Bureau  of  Plant  Industry  Bui.  55.     (N.  Y.)  Geneva  Bui.  loi, 
pp.  83,  84;  Bui.  138,  pp.  632,  634. 


OBSTRUCTIONS   TO    DEVELOPMENT 


123 


4.  Insects. — The  Flea-beetle  {Crepidodera  {Epi- 
trix)  cucumeris)  (Fig.  39). — These  small  insedls  often 
cause  more  loss  than  the  potato 
beetles.      They    perforate    the 
leaves  (Fig.  40)  during  a  critical 


FIG.   39  —  THE     CUCUMBER 

FLEA-BEETLE  {Crepidodera 
{Epitrix)  cucumeris) 
(After  Chittenden) 
Highly  magnified.    The  insect 
is  barely  one-eighth  inch  long. 
The  damage  done  by  this  iii- 
.sect     is     considerably    under- 
estimated. 

period  of  the   plant's 
life.     The   holes  pro- 
duced are  used  by  the   p,^  ^o-leaflet  of  potato,  show- 
spores   of    both   early   i^q  over  a  hundred  holes  made 
and    late     blight    for  by  flea-beetles 

entrance  into  the  leaf.  The  ease  with  which  this  damage  might  be 

....  overlooked  is  evident.     These  holes  make 

i\.rsenicai  poisoning  is  suitable  avenues  for  the  entrance  of  spores 

usually      first      noticed  °^  disease,  and  pave  the  way  for  the  rapid 

.  destruction  of  the  plant. 

on    the     margins     01 

these  holes.     At  no  time  in  their  life  history  can  these 

insedls  be  readily  destroyed.     They  dislike  Bordeaux 


124  THE    POTATO 

mixture ;  hence,  the  only  known  means  of  reducing 
their  ravages  is  to  spray  the  plants  with  this  material. 

NUMBER    OF    FLEA-BEETLE     PUNCTURES     IN     50     LEAFLETS     FROM 
12    ADJACENT    ROWS   ' 

Ptinctures 

Row  I. — Sprayed  with  very  weak  Bordeaux  mixture  .  1,794 
Row  2. — Sprayed  with  very  weak  Bordeaux  mixture  and 

soap 1,071 

Row  3. — Not  Sprayed 2,511 

Row  4. — Sprayed  with  strong  Bordeaux  mixture  .  .  1,194 
Row  5. — Sprayed   with   strong    Bordeaux   mixture  and 

soap 1,090 

Row  6. — Sprayed  with  weak  Bordeaux  mixture    .     .     .  1,295 

Row  y. — Sprayed  with  weak  Bordeaux  mixture  and  soap  901 

Row  8.— Not  sprayed 2,287 

The  grubs  of  the  flea-beetle  infest  the  tubers  and 
roots  of  potatoes,  doing  some  damage  and  causing  the 
trouble  known  as  "  pimply  potatoes."" 

In  the  Pacific  Coast  the  flea-beetles  {Epiirix  siibcri- 
fiita,  Lee,  and  E.  hirtipemiis,  Mels. )  sometimes  reduce 
the  yield  50  per  cent,  by  their  ravages.  As  they  are 
leaf-eaters,  the  foliage  should  be  sprayed  or  dusted  with 
an  arsenical  poison.  One  pound  of  Paris  green  to  150 
gallons  of  water  per  acre  is  suggested,'  but  it  is  better 
to  apply  the  Paris  green  in  Bordeaux  mixture. 

The  Potato  Beetle,  Colorado  Potato  Beetle, 
OR  Potato  Bug  {Doryphora  decemlineata) . — Until  1850 
this  insecft  was  confined  to  Mexico  and  the  Rockies. 
In  1859  its  eastward  movement  was  noted,  and  it  is 
now  well  distributed.     A  related  species  {D.  jtmda) 


1  Vt.  BuL  72,  pp.  6-9.  "  (N.  Y.)  Geneva  Bui.  113,  pp.  312-317. 

^CaL  BuL  135,  p.  29. 


OBSTRUCTIONS   TO    DEVELOPMENT  1 25 

retreated  before  its  advance,  and  is  now  more  common 
in  the  South.  In  New  Mexico'  a  parasite  lives  on  the 
eggs  and  larvae.  The  eggs  are  laid  on  the  potato 
leaves,  on  which  the  young  "bugs"  live,  chewing 
holes  in  or  eating  the  whole  of  the  leaf.  The  insedls 
are  most  adlive  about  blossoming-time,  and  do  con- 
siderable damage  if  left  alone. 

Modes  of  Combatting. — The  leaf  should  be  thoroughl)'- 
coated  with  a  poison,  generally  an  arsenical  compound 
being  used.  The  poison  should  be  applied  as  soon  as 
the  "  bugs  "  hatch,  because  the  younger  the  "  bugs  " 
the  more  easily  they  are  destroyed.  Various  arsenical 
compounds  are  used — as,  Paris  green,  arsenate  of  lead, 
and  others.  ' '  Bugs ' '  objedl  to  Bordeaux  mixture, 
hence  in  applying  the  poison  it  is  found  to  be  good 
pra(5lice  to  apply  Bordeaux  mixture  at  the  same  time. 
The  whole  of  the  plant  should  be  covered,  because  if 
badly  sprayed  the  bugs  live  on  the  unsprayed  foliage. 
The  standard  application  '\s  %  \.o  yi  pound  of  Paris 
green  to  50  gallons  of  mixture.  Generally  i  pound  of 
Paris  green  is  sufficient  per  acre,  and  if  it  is  desired  to 
apply  more  than  100  gallons,  the  proportion  of  Paris 
green  .should  be  varied  accordingly.  If  desired,  Paris 
green  may  be  applied  in  the  dry  form  by  means  of  a 
powder  gun,  the  Paris  green  being  mixed  with  flour, 
land  plaster,  etc.,  as  desired.  About  50  cents  per  acre 
should  cover  the  cost  of  one  application. 

The  Potato  Worm,"  also  known  in  the  South  as 
the  tobacco-leaf  miner  {Gelechia  operculella,  Zell.),  is 
estimated  to  destroy  25  per  cent,  of  the  potato  crop 


'  American  Naturalist,  iS99,pp.  927-29.     New  Mexico  Bui.  33,  pp.  47-51. 
2  Cal.  Bui.  135,  pp.  5-29. 


126  THE   POTATO 

on  the  Pacific  Coast.  Great  losses  often  occur  in  stor- 
age as  well  as  in  the  field.  The  moths  fly  at  night, 
and  la}'  eggs  on  the  stalks  and  tubers.  Destru<5lion  of 
the  moths  l^y  trap  lanterns,  the  destruction  of  infested 
stems,  careful  hilling  of  potatoes,  getting  them  under 
cover  as  soon  as  dug,  cleaning  up  the  refuse  of 
the  field,  and  a  rotation  of  crops  is  recommended. 
In  storage,  fumigation  with  i}{>  pounds  of  carbon 
bisulphide  per  thousand  cubic  feet  of  air-space  will 
destroy  all  the  larvae  if  repeated  five  times  at  intervals 
of  two  weeks.  This  gas  is  inflammable,  and  no  lights 
must  be  taken  near.  It  is  a  heavy  gas,  and  sinks  from 
the  top  of  the  building. 

Potato  Stalk  Weevil  '  (  Tridwbaris  trmotata). — 
This  beetle  attacks  the  stalks,  causing  them  to  wilt. 
It  is  found  from  Canada  to  Texas  and  Florida.  The 
vines  should  be  destroyed  as  soon  as  attacked,  and 
weeds  belonging  to  the  potato  family  kept  down. 

Another  insedl  has  caused  similar  trouble  in  Maine. ^ 

Grasshoppers  {Alelanophis  sp.)  do  much  damage 
during  some  seasons,  especially  after  the  hay  crop  is 
cut,  by  severing  parts  of  the  leaves.  Bordeaux  mix- 
ture containing  an  arsenical  poison  is  the  best  deter- 
rent, being  better  than  the  arsenical  compound  alone. 

The  June  Bug  {Lachnostcrna  .sp.). — The  big  white 
larvae  of  these  beetles  often  eat  the  tubers.  They  are 
most  prevalent  on  land  which  has  been  in  grass, 
although  if  land  is  in  clover  but  one  or  two  years  less 
trouble  may  be  expe<5led. 


'  Consult  V.  S.  D.  A.  Div.  of  Entomology,  Bui.  33,  6.    Ind.  Report,  1895. 
Kan.  Bui.  82.     Pa.  D.  A.  Report,  1896.     N.  J.  Bui.  109,  pp.  25-32. 
2  Me.  Report,  1897,  p  173. 


OBSTRUCTIONS   TO   DEVELOPMENT  1 27 

Wireworms  injure  potatoes  by  boring  through  them. 
They  are  more  prevalent  on  land  which  has  been  in 
grass  a  few  years.  Frequent  rotation  and  fall  plowing 
are  advised  for  both  of  these  pests. 

Other  insedls  injurious  to  potatoes  include:  Striped 
Blister  Beetle,  or  "Old-fashioned  Potato  Bug"  {Epi- 
cauta  vittata).  This  inse(5l  should  be  combatted  in  the 
same  way  as  the  Colorado  potato  beetle — by  applica- 
tions of  arsenical  poisons  to  the  foliage.  The  Tomato 
Worm  and  Cutworms  are  injurious.  The  latter  are 
very  destrucflive  at  times,  and  the  best  remedy  seems 
to  be  to  place  bait,  made  of  moist  bran  and  sugar, 
poisoned  with  Paris  green  in  the  fields. ' 

Arsenical  Poisoning. — Paris  green,  London  pur- 
ple, and  other  arsenical  compounds  usually  carry  their 
arsenic  in  an  insoluble  form,  but  some  may  be  soluble. 
This  soluble  arsenious  oxide  may  burn  the  leaves,  espe- 
cially the  tips  where  the  mixture  flows,  and  the  edges 
of  mutilated  leaves,  causing  death  of  the  spot  and  a 
' '  target-like  ' '  appearance  of  the  leaf. 

Remedy. — Do  not  use  more  than  i  pound  of  Paris 
green  per  acre,  dissolved  in  100  to  200  gallons  of  Bor- 
deaux mixture.  The  trouble  is  most  prevalent  where 
people  half  spray  and  use  Paris  green  alone,  or  i 
pound  of  Paris  green  in  one  barrel  (50  gallons)  of 
water  and  lime  or  Bordeaux  mixture. 


N.  J.  Bui.  109;  Report,  1S95,  p.  366. 


CHAPTER  XI 
SPRAYS  AND  SPRAYING 

Fungicides  are  materials  used  to  combat  fungi,  or 
small  plants  which  are  usually  parasitic. 

Bordeaux  mixture  is  the  leading  fungicide  for  pota- 
toes. The  ingredients  for  making  this  mixture  are 
freshly  slaked  lime  and  copper  sulphate.  The  fungi- 
cidal value  lies  in  the  copj)er  compound.  The  lime  is 
added  to  prevent  the  copper  sulphate  burning  the  foli- 
age, and  to  make  the  mixture  more  adhesive  and  more 
readily  seen  when  applied.  The  amount  of  lime  and 
copper  sulphate  used  vary  considerabl3^  Not  less  than 
2  pounds  of  lime  can  be  used  to  3  pounds  of  copper 
sulphate.  Excess  of  lime  is  disadvantageous  in  some 
ways,  as  it  renders  the  mixture  less  efficient  by  making 
it  thicker,  and  in  this  way  more  liable  to  settle'  and 
more  difficult  to  apply,  causing  nozzles  to  clog,  but  in 
a  wet  season  an  excess  of  lime  is  desirable.  A  thin 
mixture  can,  however,  be  more  uniformly  applied. 

Use  freshly  burnt,  clean,  firm  lime;  slake  it  by  pour- 
ing water,  preferably  hot,  over  it  in  small  amounts  at 
a  time,  until  the  lime  has  fallen  to  a  fine  powder  ; 
then  add  enough  water  to  make  a  thin  paste.  A 
large  quantity  of  lime  may  be  slaked  at  one  time  and 
kept  covered  with  water.     This  is  a  "  stock  solution." 

To  dissolve  copper  sulphate,  it  should  be  placed  in  a 


(N.  Y.)  Geneva  Bui.  243,  p.  320. 
128 


SPRAYS   AND    SPRAYING  1 29 

coarse  sack  and  suspended  in  the  top  of  the  water  in  a 
wood,  brass,  or  porcelain  vessel — usually  a  wooden 
barrel,  as  it  corrodes  iron.  The  copper  sulphate  sinks 
in  the  w^ater  as  it  dissolves,  and  a  gallon  of  water  will 
dissolve  3  pounds  of  copper  sulphate.  This  is  a  satu- 
rated solution.  If  6, pounds  of  copper  sulphate  are  re- 
quired to  a  barrel  of  water,  2  gallons  of  this  stock 
solution  should  be  used. 

Mixing. — It  is  economical  to  have  an  elevated  stage, 
under  or  alongside  of  which  the  spray-cart  may  be 
drawn.  Place  four  50-gallon  barrels  on  this  stage, 
two  of  which  are  for  the  stock  solutions  of  lime  and 
copper  sulphate,  and  two  for  making  the  mixture. 
To  make  50  gallons  of  Bordeaux  mixture,  pour  2  gal- 
lons of  copper  sulphate  saturated  solution  into  one 
barrel  and  fill  it  up  to  the  25-gallon  mark  with  w^ater. 
Stir  up  the  stock  solution  of  lime  and  dip  out  as  much 
as  is  required;  if  5  pounds,  then  the  solution  equivalent 
to  this  amount;  strain  it,  to  exclude  particles  which 
might  clog  nozzles,  into  the  lime-mixing  barrel,  and 
fill  up  to  the  25-gallon  mark  and  stir.  The  mixing- 
barrels  should  be  provided  with  2-inch  or  3-inch  rubber 
hose,  one  end  of  which  is  attached  in  an  opening  near 
the  bottom  of  the  barrel,  the  other  free.  When  read)% 
put  the  hose  from  each  barrel  into  the  spray-tank,  and 
let  them  empty  and  mix  together.  The  rubber  hose 
should  be  long  enough  so  that  the  free  end  can  be 
turned  over  into  its  barrel  w^hen  not  in  use.  If  desired, 
the  stock-solution  barrels  may  be  placed  above  and 
over  the  mixing-barrels,  so  that  dipping  out  solution 
is  avoided;  it  may  be  run  out  through  a  faucet. 
Convenience  to  a  water-supply  expedites  the  w'ork. 


130  THE   POTATO 

Testing  Bordeaux  Mixture. — In  pradlice  little 
attention  is  paid  to  the  quantity  of  lime,  except  that 
sufficient  is  added  to  combine  with  all  of  the  copper 
sulphate.  To  determine  when  this  has  taken  'place 
the  potassium  ferrocyanide  test  is  made.  Purchase 
ten  cents'  worth  of  potassium  ferrocyanide,  or  yellow 
prussiate  of  potash,  and  dissolve  it  in  water.  Isabel 
it  ' '  Poison. ' '  Stir  the  Bordeaux  mixture  in  the  spray- 
tank  and  take  out  a  sample  in  a  small  vessel,  to  which 
add  a  drop  of  potassium  ferrocyanide.  If  no  change 
in  color  is  noted  where  it  dropped  there  is  sufficient 
lime,  but  it  is  better  to  add  lime  solution  equivalent  to 
a  pound  of  lime  more.  If  the  drop  changed  the  color 
of  the  solution  reddish  brown  it  shows  that  there  is 
not  enough  lime. 

Strength  of  Solution.  —  For  potatoes,  i  pound 
of  copper  sulphate  to  7  or  8  gallons  of  water  is  com- 
monly used;  that  is  : 

Copper  sulphate  (blue  vitriol),  6  pounds. 

Quicklime  (not  slaked).  4  to  6  pounds. 

Water,  48  to  50  gallons. 

Bordeaux  Dust,'  or   Dry   Bordeaux   Mixture, 

can  be  made  in  two  ways  : 

1 .  Slaking  the  lime  by  pouring  a  strong  solution  of 
copper  sulphate  over  it. 

2.  Mixing  the  strong  copper  sulphate  solution  with 
freshly  slaked  lime  which  has  been  made  into  a  paste, 
then  placing  the  mixture  in  a  bag  and  drying  and  pul- 
verizing it.  The  two  ingredients  must  be  well  mixed 
and  passed  through  a  fine  sieve.  Dry  Bordeaux  is 
offered  for  sale  under  various  names.     Adler's   Bor- 


1  For  details,  see  Missouri  Bui.  60.    (N.  Y.)  Geneva  Bui.  243,  p.  325. 


SPRAYS    AND   SPRAYING  131 

deaux  is  reported  to  be  as  efficient  as  newly  mixed,' 
but  generally  these  preparations  are  much  inferior  to 
the  newly  prepared,  and,  when  applied  drv,  are  less 
effective  than  in  the  wet  form. 

Washing  Soda  and  Copper  Sulphate  Mixture. 
— This  mixture  is  being  used  with  success  in  parts  of 
Europe.  It  does  not  clog  nozzles,  spreads  evenly  over 
the  leaf,  and  is  easily  and  cheaply  prepared.  The 
washing  soda  is  dissolved  in  water,  poured  into  the 
barrel  of  water  and  stirred,  and  the  copper  sulphate 
added  and  stirred.  Various  strengths  are  in  use,  but 
the  most  satisfadlory  one  for  American  conditions  has 
yet  to  be  determined.  We  are  trying  4  pounds  of  cop- 
per sulphate,  6  pounds  of  washing  soda,  and  50  gallons 
of  water,  adding  i  pound  of  lime  if  Paris  green  is  used. 
A  little  over  i  pound  of  washing  soda  might  be  suffi- 
cient to  neutralize  the  4  pounds  of  copper  sulphate,  but 
it  is  safer  to  use  more.  In  Ireland  5  pounds  are  used 
and  for  three  successive  years  in  extended  trials  this 
mixture  has  given  better  results  than  Bordeaux  mix- 
ture.^ At  (N.  Y.)  Geneva  Station,  in  1904,  it  was  not 
so  good  as  ordinary  Bordeaux  mixture. 

Spraying  with  Bordeaux  Mixture. — Benefits. — 
Spraying  with  Bordeaux  mixture  influences  the  potato 
crop  in  the  following  ways  : 

1 .  The  strucflure  ^  of  the  leaf  shows  a  slight  increase 

in  thickness  and  in  strength,  and  so  offers  more 
resistance  to  the  growth  of  disease  spores. 

2.  The  chlorophyll,'  or  green  coloring  matter  of  the 

leaf  and  stem,  is  increased. 


1  Me.  Bui.  73,  p.  55.  ■■'  Department  of  Agric.  for  Ireland  I<eaflet,  14. 

3  Frank  &  Kruger.    K.  S.  R.,  VI.,  p.  306. 


132  THE   POTATO 

3.  The    transpiration'    of    moisture    is    greater    in 

sprayed  plants.  Food  is  moved  from  the  roots 
to  the  leaves  in  water,  the  food  is  worked  over, 
and  the  water  is  given  off.  The  more  food- 
laden  moisture  passing  through,  the  greater  is 
the  growth. 

4.  The  assimilation '  or  taking  in  of  food  from  the 

air  by  the  leaves  is  much  greater. 

5.  The  duration  '  of  the  leaves  and  vines*  is  greater. 

6.  The  growing  period^  is  extended  (Fig.  41),  insur- 

ing a  heavier  yield.  In  Vermont  blight  often 
appears  in  August,  and  from  then  on  the  pota- 
toes have  grown  50  bushels  a  week  when  the 
foliage  was  preserved. 

7.  The  tuber  produdlion'  is  increased,  due  to  increase 

in  the  size  of  the  tubers'  and  the  number  of 
tubers  per  plant.  Jones  &  Morse,"  of  Vermont, 
show  that  the  average  yield  for  thirteen  years 
(189 1  to  1904),  without  spraying,  was  171 
bushels  per  acre,  while  the  sprayed  plats  yielded 
286  bushels  per  acre,  or  an  average  annual  gain 
of  115  bushels  per  acre. 

8.  The  dry  matter"  is  increased. 

9.  Starch  formation'  in  the  tuber  is  considerably  in- 

creased.    At  Geneva,  (N.  Y.)  Experiment  Sta- 
tion" an  increase  of  7  per  cent,  was  obtained. 
10.   Where  there  is  no  disease'  the  yield  may  be  in- 


'  Frank  &  Kruger.    E  S.  R.,  VI.,  p.  306  2  yt.  Report,  1899,  p.  156. 

^  Vt.  Bui.  40,  pp.  26,  27  ;  Report,  1899,  p.  272.     Can.  Exp.  Farms  Report, 

1901,  p   120. 
*  (N.  Y.)  Geneva  Bui.  221.  ^  Vt.  Bui.  106,  p.  231. 

6  (N.  Y.)  Geneva  Bui.  221. 
'  E.  S.  R.,  Vol.  IX.,  p.  765.  (N.  Y.)  Geneva  Bui.  123,  p.  234. 


s      v:     ^ 


134  '^^E   POTATO 

creased  by  spraying,  due  to  increased  vigor  of 
the  plants.  At  the  Vermont  Experiment  Sta- 
tion,' in  1900,  the  yield  was  increased  73  bushels 
per  acre  by  spraying,  although  blight  did  not 
appear  that  year. 
Time  of  Spraying. — Thoughtfulness,  thorough- 
ness, and  timeliness  are  essential  to  success.  A  man 
must  watch  his  crop,  the  season,  and  conditions;  know 
for  what  he  is  spraying,  and  do  it  intelligently  as  well 
as  thoroughly.  In  wet  years  spraying  should  begin 
earlier  than  in  dry.  The  first  spraying  should  be  given 
early  enough  to  ward  off  the  first  attack.  At  Vermont 
Experiment  Station,  in  1900,"  three  applications  were 
most  economical,  but  the  first  one,  that  of  July  26,  was 
the  most  important,  as  half  the  entire  gain  was  due  to 
it;  the  sprayings  on  August  17  and  September  8  were 
of  about  equal  importance.  At  the  same  station,^  in 
1903,  one  timely  spraying  on  August  10  insured  again 
of  124  bushels  per  acre.  Some  growers  who  sprayed 
twice  in  July  secured  little  benefit,  because  by  the  time 
the  blight  appeared,  the  latter  half  of  August,  their 
plants  were  unprotecfled.  No  rule  can  be  given;  each 
man  must  watch  for  himself.  In  some  distri(5ls  it  is 
profitable  to  give  the  first  spraying  when  the  plants  are 
6  inches  tall,  and  repeat  every  ten  to  fourteen  days,  or 
as  conditions  demand. 

Number  of  Sprayings. — At  (N,  Y.)  Geneva  Ex- 
periment Station,'  in  1903,  spraying  potatoes  five  times 
gave  an  increase  of  30  bushels  per  acre  over  three  times, 
and  three  sprayings  increased  the  yield  88  bushels  per 


I  Vt.  Report,  1900,  p.  272.  ^  Vt.  Report,  1900,  p.  273. 

'  vt.  Bui.  106,  p.  231.  *  (N.  Y.}  Geneva  Bui.  241,  p.  262. 


SPRAYS   AND   SPRATIN®  1 35 

acre  over  no  spraying.  At  Cornell  Experiment  Sta- 
tion '  one  application  of  Bordeaux  mixture,  and  three 
of  Bordeaux  mixture  and  Paris  green,  increased  the 
yield  103  bushels  per  acre,  while  another'  year  six 
sprajdngs  increased  the  yield  48  bushels  per  acre. 
At  Vermont  Experiment  Station'  two  applications 
have  in  general  proved  most  profitable.  The  (N.  Y. ) 
Geneva  Experiment  Station  recommend,  as  the  re- 
sult of  their  trials  to  the  year  1904,  that  spraying  com- 
mence when  the  plants  are  6  to  8  inches  tall  and 
thorough  applications  to  be  made  at  intervals  of  ten  to 
fourteen  days  during  the  season,  making  five  to  seven 
applications  in  all. 

Insecticides  are  materials  used  to  destroy  injurious 
insedls.  Poison  is  spread  on  the  leaves  to  destroy 
leaf-eating  insedts,  and  materials  that  kill  by  contadl 
are  used  against  insedls  that  suck  plant-juices.  For 
poisoning  the  first  class  there  are  on  the  market  a 
number  of  preparations,  which  may  be  grouped  as 
follows:^ 

1.  Standard  Remedies. — Scheele's  Green,  Paris  Green, 

London  Purple,  Hellebore. 

2.  Commercial  Substitutes. — Paragrene,   Green   Arsen- 

oid,    Green   Arsenite,    Pink    Arsenoid,    Laurel 
Green,  Arsenate  of  Lead,  Disparene. 

3.  Home-made  Remedies. — Arsenite  of  Lime,  Arsenite 

of  Soda,  Arsenate  of  Lead,  Arsenite  of  Lead. 

4.  Proprietary  Remedies. — Bug  Death, ^  Black  Death,' 

Hammond's  Slug  Shot,  ^  Quick  Death,  Knobug, 


1  (N.  Y.)  Cornell  Bui.  140,  p.  402.    «  (N.  Y.)  Cornell  Bui.  196,  p.  48. 

^   Vt.  Bui.  106,  p.  230.  *  From  (N.  Y.)  Geneva  Bui.  243,  p.  329. 

^  For  analysis,  see  (N.  Y.)  Geneva  Bui.  190,  p.  2S9. 


136  THE    POTATO 

etc.     In  most  of  these  the  amounts  of  arsenical 
compounds  present  is  small. 
Contafl  Remedies — Siajidard. — Whale  Oil  Soap,   Car- 
bon Bisulphide,  etc. 

While  some  of  the  poisons  in  Group  4  (proprietary) 
have  value,  they  are  too  expensive,  and  the  work  of 
various  experiment  stations  shows  that  Paris  green  or 
arsenate  of  lead  are  cheaper  and  generally  much 
more  effective  poisons. ' 

Paris  green  rarely  occurs  on  the  market  pure.  In 
New  York  the  law  requires  that  it  contain  50  per  cent, 
of  arsenious  oxide  or  white  arsenic.  Often  some  of 
this  arsenic  is  soluble  in  water,  and  in  such  cases  it  is 
liable  to  burn  foliage.  If  more  than  4  per  cent,  of 
water  soluble  arsenic  is  present  the  sample  should  be 
condemned. 

Paris  green  tends  to  sink  to  the  bottom  of  the  spray- 
barrel;  hence,  unless  kept  well  stirred,  the  concen- 
trated solution  applied  at  the  last  may  burn  the  foliage. 
It  should  be  applied  at  the  rate  of  about  i  pound  per 
acre,  in  not  less  than  100  gallons  of  Bordeaux  mixture. 
When  applied  dry,  mix  i  pound  of  Paris  green  with 
50  pounds  of  land  plaster,  flour,  slaked  lime,  or  any 
other  dry  powder. 

At  (N.  Y.)  Geneva  Experiment  Station,  in  1904, 
Paris  green  was  applied  to  potatoes  at  the  rate  of  3 
pounds  per  acre  in  150  gallons  of  water.  Four  appli- 
cations were  made  during  the  season,  and  no  injur>'  to 
the  foliage  occurred.  The  results  show  that  Paris 
green  is  of  distindl  fungicidal  value,  and  that  it  in- 


1  Me.  Bui.  68,  87, . 


SPRAYS    AND    SPRAYING  I37 

creased  the  yield  of  potatoes  from  175  bushels  per  acre, 
on  plats  where  bugs  were  removed  by  hand,  to  221 
bushels  per  acre,  and  that  it  was  better  applied  in 
water  than  in  lime  water. 

Lead  Compounds. — Insoluble  arsenate  and  arsen- 
ite  of  lead  are  recommended  because  they  contain  no 
injurious  soluble  arsenic,  a  heavy  dose  will  do  no 
harm,  they  lead  all  other  materials  in  remaining  in 
suspension,  they  adhere  to  the  foliage,  and  they  can 
be  easily  made  at  home  and  their  purity  insured.  The 
articles  required  are  sugar  of  lead  (acetate  of  lead), 
costing  ']}{,  cents  per  pound,  wholesale,  and  arsenate 
of  soda,  costing  5  cents  per  pound,  wholesale,  at  pres- 
ent. They  may  be  dissolved  in  cold  water,  but  for 
quick  solution  hot  water  is  better.  The  formula  for 
making  i  pound  of  arsenate  of  lead — enough  for  100 
gallons — is: 

Dissolve  24  ounces  of  sugar  of  lead  in  i  gallon  of 
cold  water,  and  10  ounces  of  arsenate  of  soda  in  3 
quarts  of  water,  both  in  wooden  vessels.'  When  dis- 
solved, pour  together  into  the  spraying-tank.  Pre- 
pared in  this  way,  it  is  superior  to  any  ready  prepared 
sample.  Of  the  latter  there  are  several  makes,  which 
ma}'  be  used  if  but  a  small  amount  is  required.  ' '  Swift's 
Arsenate  of  Lead  ' '  may  be  purchased  in  a  white 
powder  form  or  as  a  paste;  it  is  easily  mixed  with 
water,  but  both  forms  settle  more  quickly  in  the  spra}-- 
tank  than  the  freshly  made.  Disparene  retails  at  25 
cents  per  pound,  and  is  a  heavy  white  paste  which 
finally  mixes  well  with  water,  but  takes  some  time. 


1  Cal.  Bui.  151.    (N.  Y.)  Geneva  Bui.  243. 


138  THE   POTATO 

It  has  great  adhesive  power,  and  will  not  burn  foliage. 
The  Adler  lead  compounds  are  similar. 

Arsenite  of  lead  is  made  by  dissolving  separately  12 
ounces  of  sodium  arsenite  and  4  pounds  of  sugar  of 
lead,  then  pouring  them  into  150  gallons  of  water. 
The  home-made  mixture  remains  in  suspension  longer 
than  the  prepared.  Pink  arsenoid  is  arsenite  of  lead 
colored;  it  is  no  more  dangerous  to  foliage  than  Paris 
green,  and  is  cheap.  It  will  remain  in  suspension  about 
twice  as  long  as  Paris  green. 

Green  arsenoid  (copper  arsenite)  sometimes  con- 
tains considerable  soluble  white  arsenic,  and  is  then 
dangerous  to  foliage,  especially  in  a  drj'  climate  or 
time. 

White  arsenoid  (barium  arsenite)  is  dangerous  to 
foliage. 

Calco  green  and  laurel  green  do  not  contain  enough 
arsenic  to  render  them  of  much  value,  and  some  sam- 
ples cause  serious  injury-  to  foliage.' 

Paragrene  is  a  prepared  compound  containing,  in 
some  cases,  considerable  soluble  ' '  white  arsenic, ' '  which 
is  objedlionable. 

Arsenic  and  lime  is  a  cheap  mixture.  Boil  i  pound 
of  white  arsenic,  costing  7  cents  per  pound,  with  2 
pounds  of  lime  in  2  gallons  of  water  for  forty  minutes 
and  add  to  150  or  200  gallons  of  water.  It  cannot  be 
safely  applied  alone,  even  with  the  addition  of  consid- 
erable lime,  but  may  be  used  in  Bordeaux  mixture. 
The  copper  sulphate  in  the  Bordeaux  mixture  seems 
to  prevent  the  caustic  adlion.  If  the  lime  and  arsenic 
fail  to  combine,  the  mixture  is  dangerous. 

'  Vt.  Report,  1899,  p.  271.    Cal.  Bui.  151,  p.  24. 


SPRAYS   AND    SPRAYING 


139 


Cost  of  Spraying  and  Profits  Derived. — In  1903, 
at  the  farm  of  J.  V.  Salisbury  &  Son,  Phelps,  N.  Y., 
the  total  expense  of  spraying'  14  acres  five  times  was 
$55-76,  the  items  being  as  follows: 


504  pounds  of  copper  sulphate,  at  6  cents 
8  bushels  of  lime,  at  35  cents 
12  pounds  of  white  arsenic,  at  5^  cents 
55  hours'  labor  for  man,  at  17%  cents 
47  hours'  labor  for  team,  at  173^  cents 

Wear  of  sprayer        


$30.24 

2.80 

.66 

9-63 
8.23 
4.20 

Cost  of  spraying  per  acre  for  each  application  was 
80  cents. 

Bushels 

Yield  of  sprayed  rows,  per  acre 147 

Yield  of  unsprayed  rows,  per  acre    ....       83 

Increase  in  yield  per  acre    .......       64 

A  good  showing,  con.sidering  that  there  was  no  blight 
this  year. 


64  bushels  per  acre  on  14  acres  (S96  bushels),  worth 
Less  cost  of  spraying 


$448.00 

55.7(J 


Net  profit  on  14  acres $392.24 

Net  profit  per  acre 28. 01 

Mr.  Salisbury  sprayed  potatoes  for  his  neighbors  at 
80  cents  per  acre  and  furnished  everything.  In  other 
experiments  conducted  in  1 904  by  the  Geneva  Experi- 
ment Station,  the  cost  of  each  application  was  as  low 
as  61  cents  per  acre,  and  the  net  profit  as  high  as 
$60.00  per  acre. 


(N.  Y.)  Geneva  Bui.  241,  p.  275. 


140 


THE   POTATO 


Spraying  Machines.' — A  spraying  outfit  consists 
of  a  pump,  nozzle,  agitator,  tank  rods,  hose,  crop-spray- 
ing attachments,  etc.  The3'  are  made  in  various  sizes, 
and  are  known  as  knapsack,  carried  and  worked  by  a 
man;  barrel,  hauled  by  man  or  horse  (Fig.  42),  and 
worked  by  manual  labor;  and  power  sprayers,  in  which 
the  pumping  is  done  by  gearing  from  the  wheels,  steam 


"bw^ 


FIG.   42 — A    SUGGESTIVE    ENGLISH    SPRAYING    MACHINE 
Emphasis  is  laid  upon  coating  the  under  surface  of  the  leaves,  and  experi- 
ments show  that  it  is  profitable  to  do  so  under  British  conditions. 


or  gas  engines,  compressed  air  or  carbon  dioxid.  The 
pressure  is  generated  in  the  pump;  100  to  120  pounds 
pressure  per  square  inch  gives  a  much  finer  spray  than 
50  to  60  pounds.  The  power  sprayers  give  the  former, 
the  manual  labor  sprayers  rarely  exceed  the  latter. 
The  working  parts  of  the  pump  should  be  of  brass  or 
bronze;  rubber  or  leather  valves,  or  any  parts  that  Bor- 


'  Consult  Mo.  Bui.  50  and  (N.Y.)  Geneva  Bui.  243. 


SPRAYS    AND    vSPRAYING  14I 

deaux  mixture  will  corrode,  are  inadmissible.  The 
pump  should  be  easy  to  clean. 

The  nozzle  and  the  pressure  determine  the  charadler 
of  the  spray.  The  Vermorel  type  of  nozzle  is  one  of 
the  best;  it  does  good  work  at  a  low  pressure  of  50  to 
60  pounds,  but  better  work  at  100  pounds.  It  does 
not  throw  the  spray  a  great  distance.  The  nozzle  used 
should  permit  of  being  readily  cleaned. 

The  agitator  may  be  (i)  mechanical  or  (2)  the  jet 
type.  The  former  is  generally  used  and  considered 
more  efl&cient,  dashers  being  used  in  barrel  outfits  and 
whirling  paddles  in  large  tanks.  The  jet  type  returns 
a  stream  of  solution  from  the  pump  to  the  bottom  of 
the  tank.  It  can  be  made  efficient  on  power  sprayers, 
but  deficiency  of  power  bars  their  use  on  hand  outfits. 

Tanks. — Cypress,  pine,  and  cedar  are  used  in  mak- 
ing tanks,  the  first  being  considered  best.  Their  ca- 
pacity varies  from  50  to  250  gallons. 

Hose. — The  hose  should  withstand  a  pressure  of  125 
pounds  per  square  inch.  Three  and  four  ply  are  most 
used.  Some  prefer  five  and  six  ply.  Half-inch  hose  is 
most  commonly  used;  some  prefer  three-eighths  of  an 
inch . 

Crop-spraying  Attachments. — The  potato  spraying 
attachment  should  carry  two  or  more  nozzles  for  each 
row.  These  should  be  capable  of  being  turned  up- 
ward when  not  in  use,  to  prevent  their  clogging  with 
sediment  while  drying.  The  spray  should  be  thrown 
upward  and  sideways,  to  coat  the  under  surface  of  the 
leaves  as  well  as  the  upper  surface.  From  two  to  six 
rows  are  sprayed  at  a  time  (see  Frontispiece  and  Fig. 
42),  and   the    attachment   should  fold  or  turn  up  to 


142  THE   POTATO 

facilitate  turning  or  going  through  a  gateway.  Sta- 
tionary nozzles  cannot  diredl  the  spray  so  well  as  hand 
nozzles;  hence,  more  should  be  put  on  to  make  sure 
that  the  plants  are  coated.  The  cost  of  the  extra 
amount  of  mixture  is -small  compared  with  the  cost  of 
the  labor  used  in  applying  it. 


CHAPTER   XII 

HARVESTING 

.  Digging. — Early  potatoes  may  be  dug  as  soon  as 
large  enough.  F'or  late  varieties  which  are  to  be 
stored  it  is  necessar}-  to  wait  until  the  tubers  have  at- 
tained full  size,  the  haulm  and  leaves  have  died,  the 
tubers  come  freel}'  from  the  stem  and  have  not  to  be 
jerked  off,  and  the  skins  are  firm  and  will  not  come 
off  easil}^  when  rubbed.  If  the  vines  have  been  de- 
stroyed b}'  blight  the  potatoes  should  not  be  dug  until 
at  least  ten  days  after  the  vines  are  dead,  as  there  is 
then  less  liabilit}'  of  rot  in  storage."  If  frost  sets  in 
early  and  the  growing  .season  has  been  late,  it  may  be 
necessary  to  dig  before  the  potatoes  are  quite  mature. 
In  this  case  the  shrinkage  in  weight,  if  stored,  will  be 
greater  than  if  they  had  matured,  and  a  reasonable  offer 
for  them  straight  from  the  field  should  not  be  declined. 
For  storage,  potatoes  must  be  dug  when  dry,  picked 
up  at  once,  and  kept  cool.  If  possible,  haul  to  some 
cool  place  at  once,  and  let  them  cool  all  night  before 
placing  in  storage.  This  is  impossible  where  large 
quantities  are  grown,  and  in  such  cases  good  ventila- 
tion of  the  storage-place  must  be  given  to  reduce  th'; 
temperature  as  quickly  as  possible. 

Methods  of  Digging. — i.  By  Fork,  Spade,  cr 
Potato-Jwok.  —  The  early  potatoes  are  often  dug  by 
hand  because  they  are  so  easily  injured.     The  skin  is 


'  Vt.  Bui.  io6,  p.  233. 


144  THE   POTATO 

tender,  the  tubers  adhere  to  the  stem,  and  often  require 
removal.  It  is  a  slow,  tedious  process,  but  nearly 
every  potato  is  obtained.  A  man  will  dig  one-eighth 
to  three-eighths  of  an  acre  a  day.  With  the  main  crop 
a  man  will  dig  from  one-tenth  to  one-half  acre  a  day  at 
a  cost  generally  varj-ing  between  two  and  six  cents 
per  bushel,  sometimes  running  to  eight  and  occasion- 
ally lower  than  two  cents,  depending  a  great  deal  on 
the  skill  of  the  man,  the  yield,  the  soil,  and  state  of  the 
land.  As  weather  conditions  may  retard  digging,  and 
labor  is  hard  to  obtain,  this  method  is  being  discon- 
tinued except  on  small  patches. 

2.  Ploiv. — Plowing  out  with  a  common  plow,  or  a 
potato  plow,  or  so-called  "digger,"  many  of  which 
are : 

Modified  Shovel  Plows. — All  that  I  have  tested  have 
been  failures.  They  dig  some  of  the  potatoes  out  and 
cover  some  up.  On  harrowing  after  them  many  more 
potatoes  appear,  and  on  digging  the  rows  some  may 
still  be  found.  My  experience  has  been  that  the  pota- 
toes left  in  would  more  than  pay  for  digging  by  hand. 
They  may  be  useful  for  small  growers  on  a  light  soil, 
and  for  those  who,  being  short  of  labor,  wish  to  save 
part  of  their  crop.  Six  to  ten  hands  and  two  horses 
will  dig  one  and  a  half  to  two  acres  per  day.  In  the 
Southern  States  early  potatoes  are  plowed  out,  and 
ten  cents  per  barrel  is  paid  for  picking  them  up. 

3.  Mechanical  Diggers. —  The  high-priced  horse- 
power diggers,  as  the  "  Reuther "  (Fig.  43),  the 
"  Hoover"  (Fig.  44),  and  the  "  Dowden,"  are  all  re- 
ported as  satisfacflory  machines.  They  work  on  the 
same  principle.     The  shovel-point  is  forced  under  the 


HARVESTING 


145 


row  of  potatoes,  and  the  row  lifted  and  deposited  on 
the  elevator,  which  gradually  shakes  out  the  soil  and 
leaves  the  potatoes  in  a  row  on  the  ground  in  the  rear. 
These  require  two  to  four  horses,  according  to  con- 
ditions, and  do  better  work  on  soils  free  from  stones. 
The  Standard  Digger  is  different.     A  divided  shovel 


FIG.  43 — THE    KEl'THER    POTATO    DIGGER 

lifts  the  row  onto  a  shaker,  which  separates  the  pota- 
toes and  soil,  leaving  the  latter  on  the  surface  behind. 
This  digger  works  well  when  potatoes  are  ridged  or 
planted  shallow,  but  when  deep  it  does  not  do  so  well.' 
One  other  form  used  successfully  in  Canada  and  Great 
Britain  consists  of  a  strong  frame  on  two  wheels  and 
a  small  wheel  in  the  front  and  rear.  It  carries  a  set  of 
revolving  forks  working  at  right  angles  to  the  share, 


1  Minn.  Bui.  52,  p.  439. 


I46  THE   POTATO 

which  pass  underneath  the  row  and  raise  it.  The 
forks  throw  the  potatoes  and  soil  against  a  screen, 
which  lets  the  soil  through  but  deposits  the  potatoes 


KIC;.   44 — THE    HOOVER    DKIGER 

in  a  row.     Several  good  diggers  are  made  on  this  plan. 
Two  or  three  horses  are  used. 

With  a  mechanical  digger,  four  to  six  acres  can  be 
dug  per  day,  and  eight  to  sixteen  hands  are  required 
to  pick  up.  The  cost  of  digging  should  not  exceed  two 
cents  per  bushel,  and  may  be  much  less.  Another  ad- 
vantage of  a  digger  is  that  if  the  land  is  clean  it  needs 
harrowing  only  to  be  in  excellent  shape  foi  seeding  to 
wheat. 


CHAPTER  XIII 
STORING 

Potatoes  may  be  stored  in  the  open  in  piles  covered 
with  straw  and  earth,  in  cellars  or  root-houses,  accord- 
ing to  the  climatic  conditions. 

Piles. — These  are  useful  for  temporary  storage  in 
the  North.  Dig  a  trench  about  3  or  4  inches  deep,  3 
feet  wide,  and  as  long  as  desired;  make  the  bottom  per- 


FIG.  45 — POTATO    SHOVEL 

fe<5lly  level  and  firm,  so  that  a  potato  shovel  (Fig.  45) 
may  be  used  on  it  when  moving  the  potatoes.  Throw 
the  soil  from  the  trench  onto  each  side,  making  a  bank 
about  15  inches  wide  with  it.  This  will  give  a  trough 
about  7  inches  deep  in  which  to  empty  the  potatoes. 
Pile  the  potatoes  neatly,  so  that  the  face  of  the  pile  at 
the  center  will  be  3  feet  or  so  high.  When  sufficient 
potatoes  are  stored,  place  about  3  inches  thick  of  rye  or 
wheat  straw  (oat  straw  being  liable  to  heat  and  become 
mouldy)  with  the  butts  down  and  heads  up  on  the 
sides  and  one  end  of  the  pile,  leaving  the  other  end 
for  additional  potatoes  (  Fig.  46) .    Then  cover  the  straw 

147 


148  THE   POTATO 

with  soil,  beginning  at  the  bottom  and  piling  it  toward 
the  apex;  2  or  3  inches  thick  will  be  sufficient  near 
the  top  with  the  straw,  and  6  or  7  inches  at  the  base. 
Finish  the  surface  off  by  patting  it  with  the  spade  so 


FIG.   46 — STORING    POTATOES    IN    I'lTS 
Useful  in  climates  where  the  winter  is  not  severe. 

that  it  will  turn  rain.  Dig  a  channel  all  around  the 
pile,  using  this  soil  for  the  covering.  The  bottom  of 
this  channel  should  be  below  the  floor  of  the  pile,  and 
have  an  outlet  to  let  off  water,  thus  insuring  a  dry  bot- 
tom for  the  pile.  Leave  the  ridge  of  the  pile  open  to 
permit  the  moisture  to  escape  when  the  potatoes 
"  sweat."     If  it  is  desired  to  hold  the  potatoes  in  these 


STORING  149 

piles  over  winter,  more  soil  or  old  hay  must  be  put 
over  them  as  the  frost  comes  on.  The  mouth  of  the 
pile  should  be  closed  at  night,  and  care  should  be  taken 
to  have  no  potatoes  left  on  the  ground  at  night.  Rain 
or  frost  may  come  on  and  injure  them,  or  retard  the 
work.  Sufficient  covering  must  be  put  on  the  piles  to 
prevent  the  rain  and  sun  discoloring  the  potatoes.  I 
have  known  a  whole  crop  ruined  by  inattention  to  this 
point.  The  rain  browns  them,  and  the  sun  makes  them 
green  and  unsalable.  This  method  is  not  advisable  in 
the  Northern  States  unless  one  is  sure  that  they  will 
not  want  to  sell  or  put  up  the  potatoes  until  spring,  as 
the  pit  cannot  be  opened  during  frost  or  in  wet 
weather,  and  in  spring  moving  potatoes  on  wet  land  is 
objectionable. 

Cellars. — If  seed  potatoes  only  are  held,  they  may 
be  kept  in  trays,  bushel  boxes,  or  barrels,  storing 
these  so  that  air  can  circulate  under  and  round  them, 
or  they  may  be  held  in  bins. 

Construction. — The  location  of  the  cellar  should 
be  dry  and  well  drained.  It  should  be  built  under- 
ground, of  concrete,  brick,  or  stone  walls,  with  a 
plastered  ceiling  if  a  building  is  above  it,  to  make  a 
dead  air-space  between  the  plaster  and  the  floor.  Con- 
crete walls  are  readily  made  with  clean  gravel,  sand, 
and  cement,  with  boards  to  hold  the  material  while  set- 
tling. Use  one  part  of  Portland  cement,  three  of  sand, 
and  six  of  gravel;  mix  the  sand  and  cement,  then  add 
the  gravel;  wet  and  mix,  and  fill  into  the  wall-space. 
To  hold  it  in  position  while  drying  it  is  customary  to 
use  I -inch  boards,  nailed  onto  2  x  4-inch  studding, 
which  may  be  placed  i  foot  6  inches  on  centers.    To  pre- 


150  THE  POTATO 

vent  sagging,  the  studding  of  one  side  is  braced  to  that 
on  the  other  side  by  J^  x  ^-inch  iron  strips,  which 
are  placed  three  feet  apart  each  way,  and  nailed  to  the 
studding  on  each  side.  These  are  left  in  the  wall,  and 
the  ends  cut  off  when  the  boards  are  taken  down. 
Apertures  through  which  to  shoot  the  potatoes  should 
be  left  at  intervals.  One  satisfadtory  cellar  of  which  I 
know  has  a  driveway  through  the  center  and  bins  on 
each  side.  The  bins  are  about  10  feet  wide  and  are 
filled  4  to  6  feet  deep.     Divisions  are  put  in  as  desired. 

Ventilation  and  Temperature  are  most  impor- 
tant. The  potatoes  must  be  kept  cool,  about  33°  F. 
being  a  favorable  temperature.  If  possible,  lead  air 
through  a  deep  underground  drain-tile  into  the  cellar; 
the  length  of  the  tile  should  be  sufficient  to  warm  the 
air  a  little  in  winter,  and  the  outside  end  of  it  vShould 
be  covered  to  prevent  the  entrance  of  vermin.  A 
ventilator  on  the  roof  will  remove  warm  air.  Have  a 
raised  board  floor  in  each  bin  and  a  ventilator  running 
from  it  up  through  the  tubers  at  intervals.  Have 
double  doors  at  the  entrance  and  the  shoots,  and  keep 
the  place  dark.  Darken  the  windows  if  there  are  any. 
A  small  cellar  can  be  made  if  desired,  but  make  the 
roof  high  enough  to  work  in — say,  8  feet.  Purchase  a 
reliable  thermometer  and  hang  it  in  the  cellar,  an  oil- 
stove  and  radiator,  and,  if  the  temperature  is  going 
down  too  low,  warm  the  place.  It  is  folly  to  have 
potatoes  freeze  to  save  ten  cents  worth  of  kerosene. 

The  advantages  of  a  cellar  are: 

1 .  You  can  see  how  the  crop  is  keeping. 

2.  The  conditions  can  be  controlled. 

3.  The  potatoes  can  be  sold  at  any  time. 


STORING  151 

Losses  in  Storage. — Potatoes  suffer  loss  in  weight 
in  keeping  in  addition  to  any  loss  due  to  disease  or 
inse(5t  attacks.  At  Cornell  University,  during  the  past 
winter,  the  variety  Sir  Walter  Raleigh,  stored  in  crates 
in  a  cool  cellar,  lost  12  per  cent,  in  weight  between 
the  date  November  6,  1903,  and  April  27,  1904,  a 
period  of  173  days,  while  the  variety  Carman  No.  3 
lost  nearly  10  per  cent.  Neither  variety  had  sprouted 
at  all.  This  seems  to  show  that  in  this  distridl  the 
latter  is  better  for  storage,  and  growers  have  noted 
this.  Sir  Walter  Raleigh  seems  better  adapted  for 
selling  from  the  field  than  for  storage.  No  doubt 
other  varieties  vary  in  the  same  way,  and  the  same 
variety  will  vary  under  differing  conditions.  At  the 
Michigan  Experiment  Station  a  barrel  of  potatoes 
stored  September,  1893,  ^^^^  lost  5  per  cent,  in  weight 
by  March  28,  and  11.5  per  cent,  by  May  i,  1894.  ^6" 
search  shows  that  these  losses  are  influenced  by  tem- 
perature and  the  state  of  moisture  of  the  air.  The 
higher  temperature  increases  the  loss,  while  the  higher 
moisture  content  diminishes  it.  I^ight  seems  to  have 
little  influence  upon  the  loss  of  weight,  but  is  injurious 
because  it  diminishes  the  selling  value  of  the  potato. 
The  average  percentage  losses  of  twelve  varieties  of 
potatoes  carefully  stored  in  a  cool  cellar  at  a  tempera- 
ture of  42°  to  51°  F.  during  seven  months,  as  recorded 
by  E.  Wollny,'  are:  Odtober,  2.02  per  cent.;  Novem- 
ber, 1. 18;  December,  .50;  January,  .50;  February,  .81; 
March,  .41;  April,  .50;  the  total  loss  aggregated,  on  an 
average,  6.17  per  cent.     In  every  case  the  losses  were 


'  E.  S.  R.,  III.,  p.  493- 


152  THE   POTATO 

greatest  diredlly  after  digging,  and  in  February  the 
losses  were  higher  than  the  month  before  or  after. 
The  size  of  the  tuber,  or  whether  the  variety  was  early 
or  late,  had  no  perceptible  influence.  The  three  early 
varieties  lost  from  4.87  to  8.48  per  cent.,  the  five  medi- 
um-early varieties  from  4.55  to  6.78  per  cent.,  and  the 
four  late  varieties  5.71  to  7.28  per  cent.  These  losses 
are  believed  to  be  lower  than  those  usually  assumed 
and  observed.  The  loss  of  weight  of  these  tubers 
from  May  to  Odlober  was  21.57  P^r  cent.,  considerably 
more  than  their  loss  from  Odlober  to  May  i .  As  soon 
as  the  sprouts  begin  to  grow  the  loss  is  rapid. 

Nobbe  found  that  about  75  per  cent,  of  the  loss  of 
potatoes  in  storage  is  due  to  loss  of  water  and  25  per 
cent,  to  respiration.  As  the  potato  is  alive  and 
breathes,  its  existence  depends  upon  its  using  some  of 
its  stored-up  energy.  A  ferment  changes  some  of  its 
starch  into  sugar,  and  this  sugar  is  used  to  furnish 
energy.  At  low  temperatures  sugar  formation  contin- 
ues, but  respiration  and  the  use  of  the  sugar  diminishes, 
and  at  30°  F.  to  28°  F.  (2°  to  4°  below  freezing-point) 
respiration  almost  ceases;  hence,  frozen  potatoes  taste 
sweet  because  of  the  accumulation  of  sugar. 

E.  Wollny  believes  that  between  32°  and  50°  F.  is 
the  best  range  of  temperature  for  holding  potatoes. 

The  adtual  losses  which  may  occur  in  storage  as  the 
result  of  disease  cannot  be  definitely  stated. 


CHAPTER  XIV 

PRODUCTION,    TRANSPORTATION,    AND 
MARKETS 

In  the  North  the  potato  is  a  quasi-staple  produdl. 
It  can  be  kept  a  number  of  months  in  storage.  In  the 
South,  except  in  cold  storage,  it  cannot  be  kept  long 
and  is  purely  a  garden-truck  crop,  hut  its  culture  is 
extending. 

2,836,196  farmers  grew  potatoes  in  1899.  I'he  area 
was  2,938,952  acres,  and  the  yield  273,328,207  bushels, 
valued  at  $98,387,614.  The  average  value  of  the 
product  per  acre  was  $33.48,  that  of  all  crops  was 
$10.04,  while  that  of  all  vegetables  was  $42.09  per 
acre.  The  price  per  bushel  varied  between  22  cents 
in  Iowa  and  Nebraska  to  $1.10  in  Arizona,  the 
average  price  being  36  cents.  The  average  3'ield '  per 
acre  in  the  year  1879  was  96.7  bushels;  in  1889,  83.6 
bushels,  and  in  1899,  93  bushels  per  acre,  although 
yields  of  300  and  400  bushels  are  common,  and  over 
800  bushels  have  been  obtained. 

In  1900  six  States  grew  51  per  cent,  of  the  potatoes 
(Figs.  47,  48) — viz..  New  York,  Wisconsin,  Michi- 
gan, Pennsylvania,  Iowa,  and  Minnesota — while  Ohio, 
Illinois,  Maine,  Kansas,  Nebraska,  Missouri,  Indiana, 
and  California  grew  25  per  cent.  more.  The  sandy 
pine  belt  region,  skirting  the  lakes,  has  shown  a  phe- 
nomenal increase   in   potato    producftion.     In    Maine, 


1  Consult  Twelfth  Census  Report   1902. 

153 


®     L. 


HI" ■; 

;  *  »     ••'i; 


w    -^ 


156  THE   POTATO 

Michigan,  Wisconsin,  and  Minnesota  the  potato  acre- 
age has  increased  faster  than  the  population  in  the  past 
ten  years.  New  York  comes  in  the  same  belt.  The 
per  capita  production  of  potatoes  in  the  United  States 
is  given  as  about  3.5  bushels.'  About  one-third  of  the 
total  crop  of  the  Southern  States  is  shipped  North  as 
early  potatoes,  and  some  late  potatoes  are  shipped  back 
from  the  North.  The  consumption  north  of  Mason  and 
Dixon's  line  is  about  4)^  bushels  per  head,  exclusive 
of  potatoes  used  for  seed  or  starch-making.  The 
South  consumes  a  relatively  small  amount,  being  less 
than  1^2  bushels  per  capita. 

Knowing  the  approximate  consumption  and  the 
area  and  condition  of  the  crop  (obtained  from  the 
United  States  Department  of  Agriculture  reports, 
which  are  posted  monthly),  the  farmer  can  form  an 
idea  of  the  outlook  of  the  business.  Thus,  in  1903 
there  were  2,916,855  acres  grown,  and  the  jaeld  as 
now  known  was  247, 127, 880 bushels.  The  table  below 
will  show  the  uses  to  which  this  crop  was  put.  In 
1904  as  large  an  area  would  need  to  be  planted  (a 
larger  one  ought  to  be,  because  the  population  is  in- 
creasing); hence,  10  bushels  of  seed  are  allowed  per 
acre  on: 

Bushels 

2,925  000  acres         29,250,000 

Plus  10  per  cent,  loss  in  storage        .     .     .       2,925,000 
Used     for    starch-making,     etc.     (largely 

small  potatoes,  etc.) 5,000,000 

Available  for  human  consumption    .     .     .   209,952,880 


247,127,880 


'  Consult  Twelfth  Census  Report,  1902. 


PRODUCTION,  TRANSPORTATION,  MARKETS      1 57 

The  public  can  consume  about  three  bushels  of  pota- 
toes per  head  per  year,  and  as  there  were  79,000,000 
people  to  be  fed,  it  would  require  237,000,000  bushels 
to  furnish  this  quantity.  The  shortage  of  27,000,000 
bushels  insured  a  fair  price,  61.4  cents  per  bushel 
being  the  average  farm  value. 

The  States  having  a  surplus  of  potatoes  are  the 
Southern  and  Eastern  Coast  States  (notably  Maine, 
Rhode  Island,  New  Jersey,  Virginia,  and  Florida), 
their  market  being  the  cities  of  the  East  and  interior. 
The  Trans-Mississippi  and  Nortwestern  States  also 
have  a  surplus. 

The  potato  trade  is  a  home  trade.  The  yield  is  sel- 
dom more  than  is  required  for  home  consumption,  and 
several  times  it  has  been  less — as  in  1902,  w^hen  over 
8,000,000  bushels  were  imported. 

Factors  Influencing  Farm  Prices. — Farm  prices 
are  the  net  value  of  farm  produces  to  the  producer  upon 
delivery  at  the  local  market.  Between  the  grower  and 
the  consumer  profits  must  be  made  by  the  local  buyer, 
the  wholesaler,  the  retailer,  and  perhaps  a  broker  or 
two,  and  the  transportation  companies.  To  yield  a 
profit  to  the  grower  the  price  received  from  the  con- 
sumer must  exceed  (i)  the  expenses  of  distribution, 
including  transportation,  (2)  the  cost  of  producftion. 
It  may  not.  The  market  price  is  regulated  by  the  law 
of  supply  and  demand. 

In  marketing  live  stock,  cotton,  grain,  tobacco,  and 
wool  the  main  tendency  is  to  eliminate  the  expensive 
middle  man.  This  is  easier  accomplished  with  non- 
perishable  products  than  with  perishable  ones.  There 
are  three  reasons  why  the  expensive  middle  man  has 


158  THE    POTATO 

been  retained  in  the  marketing  of  perishable  prod- 
ucts— 

1.  The  extraordinary  risks  of  depreciation. 

2.  Insufl&cient  capitaHzation  of  the  distribution  end. 

3.  Absence  of  large-scale  haudhng  of  the  products. 
There  is  little  consolidation  in  marketing  potatoes. 

Generally  speaking,  selling  on  commission  is  antiqua- 
ted and  should  be  abandoned,  as  it  is  the  most  demoral- 
izing feature  of  farming.  The  market  is  more  stable 
when  goods  are  bought  and  sold  outright.  An  inter- 
esting feature  is  that  rural  districts  are  doing  more  of 
their  own  banking,  so  far  as  the  financiering  of  the 
grain  and  some  other  crops  is  concerned,  and  the  same 
will  eventually  be  extended  to  potatoes.  Cold  storage 
improves  prices,  preventing  .slumps  and  excessively 
high  prices,  both  of  which  are  injurious.  High  prices 
inevitably  lead  to  reduced  consumption.  The  absence 
of  public  markets  where  consumer  and  producer  can 
meet  is  a  noteworth}-  feature  of  American  cities  and 
towns.  Such  markets  have  a  salutar}-  effect  upon  the 
distributor  and  middleman  wherever  they  exist.  The 
useless  retailers  are  eliminated  and  the  service  of  the 
survivor  is  improved,  and  both  producer  and  public 
are  benefited. 

One  important  cause  of  this  lack  of  system  is  the 
poor  roads.  Hauling  is  high.  It  costs,  on  an  average, 
25  cents  to  haul  a  ton  of  produce  a  mile,  and  in  man}' 
cases  more.  90  per  cent,  of  all  the  freight  handled 
by  the  railroads  is  brought  to  them  on  wagons;  most 
of  it  is  farm  produce.  With  team  and  man  at  $3.50 
per  day,  the  co.st  of  hauling  this  freight  aggregates 
about  as  much  as    the  cost  of  running  the  railroads 


PRODUCTION,   TRANSPORTATION,   MARKETS       1 59 

one  year.  It  is  useless  to  double  the  produdtion  of 
the  farm  unless  we  increase  the  facilities  for  market- 
ing the  produce,  and  to  do  this  it  is  imperative  that  we 
have  good  highways.  In  Belgium  loads  of  farm  prod- 
uce are  hauled  60  to  70  miles  in  competition  with  the 
railroad.  Let  ever}^  farmer  join  the  good  roads'  move- 
ment; then  he  will  be  able  to  go  to  market  with  prod- 
uce on  days  when  the  land  is  too  wet  to  work  or 
when  the  price  is  high.  How  many  miles  will  $1.25 
haul  a  ton  of  potatoes  or  other  farm  produce  on  a  road, 
a  trolley  road,  a  railroad,  and  on  water? 

$1.25  will  haul  a  ton  5  miles  on  a  common  earth 
road  ;  1 2)4  to  15  miles  on  a  well-made  macadam  road; 
25  miles  on  a  trolley  road  ;  250  miles  on  a  steam  rail- 
way;  1,000  miles  on  a  steamship. 

The  value  of  cheap  steamship  transportation  is  seen 
in  the  Eastern  potato  trade.  The  prices  of  potatoes  are 
better  sustained  in  the  Central  States  than  in  the  East- 
ern because,  although  the  tariff  of  25  cents  per  bushel 
is  an  ample  safeguard  for  the  producer,  as  soon  as 
potatoes  are  50  cents  per  bushel,  wholesale  imports  from 
Europe  and  the  West  Indies  are  apt  to  prevent  them 
from  going  much  higher. 

The  South  Atlantic  States,  from  Florida  to  Virginia, 
supply  the  early  potato  trade  of  the  Eastern  cities. 
The  water  transportation  enables  them  to  handle  large 
quantities  at  low  rates,  and  to  compete  with  Northern 
potatoes  (old)  during  at  least  three  months,  of  the 
year. 

Modes  of  Selling-. — i.  The  Local  Market. — This 
deserves  attention,  as  higher  prices  are  received  in  it 
by  the  producer  than  when  shipped  away. 


l6o  THE   POTATO 

2.  The  Distant  Market. — Many  growers  must  ship. 
For  such,  combination  is  essential.  The  method 
adopted  by  the  Eastern  Shore  potato  farmers  (Vir- 
ginia) is  noteworthy.  There  are  2,500  shippers  in  the 
Exchange.  They  sell  all  their  produce  through  seledt- 
ed  receivers,  appointed  by  the  directors,  in  New  York, 
Boston,  and  Philadelphia.  The  receivers  charge  8  per 
cent,  commission,  of  which  3  per  cent,  is  given  to  the 
agent  who  solicits  the  business.  This  agent  should 
be  familiar  with  the  market  requirement  and  give  in- 
structions in  regard  to  methods  of  grading,  assorting, 
and  packing,  and  in  this  way  render  the  produce  more 
valuable.  Combinations  such  as  the  following  com- 
mend themselves  :  the  use  of  the  "  registered  label," 
which  is  similar  to  a  "  union  label,"  and  is  placed  on 
all  packages,  or  a  trade-mark  similar  to  that  used  by 
the  Farmers'  Produce  Association,  of  Delaware,  which 
carries  the  number  of  the  shipper,  and  enables  the 
.sele(5led  salesman  to  inform  the  grower  at  once  if  any- 
thing is  wrong. 


FARMERS'  PRODUCE  ASSOCIATION 
OF  DELAWARE  (2?) 

The  contents  of  this  package  are 

GUARANTEED 

to  be  as  good  all  through  as  on  top 


Commission  Rates. — In  Cleveland  potatoes  are 
sometimes  sold  on  a  commission  basis  of  4  and  5  cents 
per  bushel,  or  10  per  cent,   of  the  sale  price.     In  St. 


PRODUCTION,  TRANSPORTATION,  MARKETS       l6l 

Louis  the  wholesaler  purchases  and  makes  his  profit 
by  selling  to  large  customers  and  hucksters  at  an  ad- 
vance of  lo  cents  per  bushel  over  what  they  cost  him 
in  car  lots. 

In  Cincinnati  the  rate  of  commission  is  3  cents  per 
bushel.  In  Kansas  City  the  brokerage  for  handling  is 
2  to  2^  cents  per  bushel.  In  Richmond,  Virginia,  and 
Atlanta,  Georgia,  if  not  sold  by  the  grower,  10  per 
cent,  is  the  commission.  In  Lincoln,  Nebraska,  when 
potatoes  retail  at  80  cents  per  bushel,  the  money  is 
divided  about  as  follows:  Retailer's  share,  20  cents; 
wholesaler's  share,  10  cents;  railroad  freight,  18  cents; 
seller's  commission,  7  cents;  net  price  to  producer,  25 
cents  ;  69  per  cent,  of  the  cost  to  the  consumer  goes 
to  pa}'  the  transporters  and  distributors,  and  31  per 
cent,  to  the  grower.  At  Portland,  Oregon,  the  com- 
mission is  5  per  cent.,  and  the  burlap  sacks  in  which 
the  potatoes  are  handled  cost  about  5  cents  each. 
The  retailers  sell  at  an  advance  of  10  to  30  cents  per 
sack  (100  pounds).  At  New  York  and  Philadelphia 
8  and  10  per  cent,  commission  will  find  good  sales- 
men. The  producer  usually  receives,  net,  between 
25  and  65  per  cent,  of  the  retail  price  of  potatoes. 
Taking  a  number  of  market  returns,  they  show  that 
the  producer's  returns  are  about  63  per  cent,  of  the 
price  paid  in  the  markets,  and  of  this,  in  some  cases, 
about  half  is  paid  to  the  railways  for  transportation  if 
the  goods  are  sent  by  rail,  so  that,  then,  roughly 
.speaking,  the  producer,  transporter,  and  distributor 
divide  the  customer's  money  equally.  The  value  of  a 
local  market,  where  the  producer  can  sell  direct  to  the 
consumer,  is  apparent. 


1 62  THE   POTATO 

Grading, — The  proper  grading  of  potatoes  is  essen- 
tial to  success.  Scabby,  second-growth,  ill-shapen, 
diseased,  and  undersized  tubers  must  be  removed 
from  first-class  grade.  The  grading  may  be  done  by 
having  a  .sand  screen  on  trestles  .set  at  such  an  angle 
that  the  potatoes  roll  down  i  ito  baskets  at  the  bottom, 
while  the  dirt  falls  through,  and  the  seconds  and  refuse 
are  thrown  into  baskets  or  boxes  on  the  side.  Let  two 
men  sort  and  one  shovel,  and  have  one  emptying  and 
bagging  if  the}-  go  into  bags.  A  sack-holder  is  a  con- 
venience in  filling  the  bag.  The  small  potatoes  and 
dirt  may  be  removed  by  a  potato-sorter  (Fig.  49),  of 
which  there  are  several  types  on  the  market. 

Packages. — Potatoes  are  sold  by  the  pound,  peck, 
bushel,  barrel,  cental,  and  car  lot.  The  early  potatoes 
are  shipped  in  barrels  holding  3  bushels  (180  pouhds). 
A  canvas  cover  is  nailed  on  the  head.  Such  barrels 
cost  about  20  cents,  including  the  cover.  The  late 
crop  is  sometimes  shipped  in  bulk  in  car  lots.  In  the 
East  seed  potatoes  are  shipped  in  double-headed  bar- 
rels containing  165  pounds,  net.  Such  barrels  cost, 
new,  about  30  to  33  cents.  Flour-barrels  are  often 
purchased  at  about  15  cents  each  instead.  The  high 
price  of  new  barrels  leads  some  to  ship  seed  potatoes 
in  strong  burlap  sacks  w^hich  hold  the  same  amount 
as  a  barrel.  The  sacks  cost  15  to  20  cents  less  than 
the  barrel.  Boxes  are  used  for  .shipping  small  quan- 
tities. On  the  Pacific  Coast  burlap  sacks  holding 
a  cental  (100  pounds),  and  costing  5  cents  each,  are 
used. 

Barrels. — Before  filling,  drive  the  hoops  firm  on  the 
bottom  and  nail  with  shingle  nails;  drive  on  the  bulge 


I 64  THE   POTATO 

hoops,  and  secure  with  3  or  4  barrel  nails;  then  pro- 
ceed to  fill.  The  potatoes  should  be  shaken  down  oc- 
casionally while  filling,  and  the  barrels  filled  full,  and, 
if  headed,  the  head  should  be  put  in  where  it  belongs 
with  a  screw  press,  so  that  the  potatoes  cannot  rattle. 
The  head  should  be  nailed  firmly  with  shingle  nails. 
If  in  bags,  sack  them  up  well,  and  tie  tight ;  or  sew 
up,  according  to  requirements. 

Bushel  Boxes. — For  marketing  early  potatoes  in 
the  local  market  bushel  boxes  or  crates  are  often 
used.  T.  B.  Terry  uses  a  bushel  box  13x16  inches 
and  13  inches  deep,  all  inside  measurement.  The 
sides  and  bottoms  are  of  ^-inch,  and  the  ends  are 
^-inch,  white  wood.  Hand-holes  are  cut  in  each 
end,  and  the  upper  corners  are  bound  with  galvanized 
hoop  iron  to  strengthen  them.  They  cost  $25.00  to 
$30.00  per  hundred  at  the  factory,  and  weigh  6  to  7 
pounds  each.  Each  box  has  a  lid,  so  that  in  change- 
able weather  the  potatoes  can  be  picked  up  and  cov- 
ered as  fast  as  dug.  This  box  holds  five  pecks.  The 
legal  bushel  for  grain  is  2,150.4  cubic  inches,  and  in 
measuring  potatoes  the  rule  is  to  heap  the  half-bushel , 
measure  sufficiently  to  add  one  level  peck  to  the  two 
level  half-bushels.  Five  level  pecks  are  held  in  2,688 
cubic  inches.  These  boxes  hold  2,700  cubic  inches 
when  level  full ;  hence,  they  maj-  be  piled  three  or 
four  high  on  a  wagon.  The  recent  introducflion  of  a 
crate  in  which  the  sides  fold  onto  the  bottom  when 
not  in  use  reduces  the  amount  of  storage  room  re- 
quired by  about  two-thirds.  These  crates  cost  the 
same  as  others,  and  appear  to  be  equally  strong. 

Advantages  of  a  bushel  box: : 


PRODUCTION,  Transportation,  markets    165 

1 .  Potatoes  are  put  in  the  boxes  and  covered  as  soon 

as  dug,  thus  preventing  them  from  heating  in 
the  sun. 

2.  They  are  easily    and  quickly  loaded  on  a  wagon, 

saving  time. 

3.  They  are  convenient  packages  in  which  to  carry 

early  potatoes  to  the  home  market. 

4.  The  potatoes  may  be  left  at  the  store  in  the  box  and 

delivered  in  the  box  when  sold,  saving  handling 
and  bruising. 

5.  When  drawing  the  main  crop  to  the  storage-cellar 

they  are  convenient  to  handle. 

6.  They  may  be  used  for  storing  seed  potatoes,  apples, 

etc. ,  and  carrying  seed  potatoes  to  the  field  to 
be  planted. 


CHAPTER   XV 

CHEMICAL   COMPOSITION   AND   FEEDING   VALUE 

Composition. — Early  attempts  were  made  to  deter- 
mine the  food  value  of  the  potato  by  means  of  chemical 
analyses.  In  1 795  Pearson  reported  ' '  Experiments 
and  observations  on  the  constituent  parts  of  the  potato 
root."  Einhof  publi.shed  analyses  of  the  potato  in 
1805,  as  did  Vanquelin  in  1817.  Rather  more  than 
fifty  years  ago  Emmons  in  this  country  reported  anal- 
y.ses.  Lawes  and  Gilbert  devoted  considerable  time  to 
the  study  of  the  composition  of  potatoes,  and  more  re- 
cently various  agricultural  experiment  stations,  nota- 
bly the  Connedticut  State  and  the  Minnesota  Agricul- 
tural Experiment  Stations,  the  Division  of  Chemi.stry, 
U.  S.  D.  A.,  and  various  European  institutions  have 
been  investigating  the  problem.  The  approximate 
chemical  composition  of  a  number  of  varieties  is : 
Water,  75  per  cent.;  protein,  2.50  per  cent.;  ether  ex- 
tract, .08 per  cent. ;  starch,  19.87  percent. ;  fibre,  .33  per 
cent.;  other  non-nitrogenous  materials,  .77  per  cent.; 
ash,  I  per  cent.  A  more  extended  analysis  is  taken 
from  the  "\''ermont  Experiment  Station,  report  1901: 

TABLE    XII 


., 

i^ 

5 

Dextrin 

and 

Soluble 

Starr  h 

Is 

^1 

s 

5^ 

Per 

Per 

Per 

Per 

Per 

Per 

Per 

Per 

Per 

Per 

cent. 

cent. 

cent. 

cent. 

cent 

cent. 

cent. 

cent. 

cent. 

cent. 

79-41 

20.59 

i4-5t 

1-35 

0.09 

0.36 

2.2S 

0.06 

1.26 

0.68 

166 


CHEMICAL  COMPOSITION  AND  MARKET  VALUE      1 67 

The  percentage  of  water  usually  ranges  between  70 
and  80  per  cent.,  the  extremes  being  65  and  85  per 
cent.  Potatoes  contain  more  dry  matter  than  any  root 
crop. 

Per  cent. 

White  turnips        7  to     9 

Rutabagas 9  to  14 

Mangel-wurzels 9  to  16 

Sugar-beets 12  to  24 

Carrots 10  to  17 

Parsnips 10  to  18 

Potatoes 20  to  30 

About  85  per  cent,  of  the  matter  is  present  in  the 
solid  portion,  or  marc,  and  15  per  cent,  in  the  juice. 
It  has  been  believed  by  many  that  the  specific  gravity 
of  the  tubers  varied  with  the  percentage  of  dry  matter, 
and  on  this  basis  tables  for  ascertaining  the  dry  matter 
present  in  the  tubers  from  the  specific  gravity  have 
been  worked  out  and  used  considerably.  From  these 
data  the  starch  content  was  determined.  Woods,'  of 
Maine,  and  Watson,"  of  Virginia,  found  that  the  ratio 
existing  between  the  specific  gravity  and  the  starch 
content  is  not  fixed. 

Starch  is  the  most  important  constituent  of  the  dry 
matter  of  potatoes;  it  generally  constitutes  15  to  20 
per  cent,  of  the  fresh  tubers,  but  may  be  as  low  as  10 
or  as  high  as  25  per  cent.  Maine-grown  potatoes  are 
usually  lower  in  their  starch  content  than  European- 
grown  potatoes.  The  starch  content  varies  wath  the 
variety  and  the  locality.  Northern-grown  samples  of 
the  same  variety  usually  contain  more  starch  than 
Southern-grown  samples.^ 

1  Me.  Bui.  57,  p.  150.  «  Va.  Bui.  55,  p.  102;  Bui.  56,  p.  144. 

3  Va.  Bui.  56,  p.  144. 


1 68 


THE   POTATO 


TABLE    XIII 
DIGESTIBILITY     OF     POTATOES 


Animal 


Potatoes,    with  eggs,    milk 

and  cream 

Potatoes,  raw  ' , 

Potatoes,  cooked 

Potatoes  dried  '■'  and  ground 


Man 
Pigs 
Pigs 
Sheep 


Per 
cent. 


s 

V 

S 

y 

IS 

.8 

4 

< 

0 

o; 

0 

Per 

Per 

Per 

Per 

cent. 

cent. 

cent. 

cent. 

90.6 

71.9 

93  0 

84-5 

82.0 

98.1 

82.0 

80.0 

97.6 

81.5 

i9-5 

92.0 

44.6 

40.0 


The  above  data  show  that  potatoes  are  almost 
wholly  digestible. 

Feeding  Value. — When  abundant  and  low^  in  price, 
potatoes  may  be  fed  to  all  classes  of  stock.  In  France, 
Girard  fed  55  to  66  pounds  of  cooked  potatoes  per  day 
to  fattening  steers  and  4;!^  to  6)^  pounds  to  sheep. 
Yon  Funke^  found  uncooked  potatoes  were  good  for  all 
stock  except  pigs.  He  fed  60  pounds  of  raw  potatoes, 
6  pounds  of  linseed  meal,  and  9  pounds  of  clover  hay, 
with  .salt,  per  i  ,000  pounds,  live  weight,  per  day  to  fat- 
tening steers.  For  milch  cows,  25  pounds  daily  per 
1 ,000  pounds,  live  weight,  is  the  limit.  For  yearlings, 
ewes,  and  wether  sheep,  25  pounds  per  1,000  pounds, 
live  weight,  per  day  is  advised,  and  fattening  sheep, 
40  pounds.  For  horses,  about  12  pounds  per  1,000 
pounds,  live  weight,  may  be  given  with  other  food. 
Stock  should  not  be  watered  soon  after  feeding  pota- 
toes, but  preferably  about  half  an  hour  before  feeding. 
Potatoes*  are  not  a  valuable  food  for  young  animals, 


1  Snyder,  Minn.  Bui.  42,  pp.  89,  90. 
a  E.  S.  R.,  v.,  p.  812. 


•^  Kellner,  et  al.   E.  S.  R.,  XIV.,  p.  595. 
*  Minn.  Bui.  42,  p.  95. 


CHEMICAL    COMPOSITION    AND    FEEDING   VAI^UE    1 69 

as  they  are  deficient  in  protein  and  ash — hence,  should 
not  be  fed  to  growing  cattle  under  two  years  old, 
lambs,  or  young  pigs,  unless  in  very  small  amounts, 
with  other  food  to  balance  the  ration.  At  Wisconsin 
Kxperiment  Station,' hogs  ate  cooked  potatoes  better 
than  uncooked,  and  445  pounds  of  cooked  potatoes  were 
equal  to  100  pounds  of  corn-meal  in  feeding  value. 
One  pound  of  dry  matter  of  corn  is  superior  to  one  pound 
of  dry  matter  of  potatoes  for  making  gains  with  pigs. 
Cooking.  —  In  cooking  potatoes  a  considerable 
portion  of  the  albumen  may  be  lost.  Peeled  potatoes 
started  in  cold  water  lost  80  per  cent,  of  albumen, 
while  those  started  in  hot  water  lost  but  10  per  cent, 
lycss  is  lost  if  the  potatoes  are  not  peeled.  Salt  should  be 
added  to  potatoes,  because  the  mineral  matter  they  con- 
tain is  deficient  in  sodium  salts,  which  are  requisite  for 
the  human  system,  and  because  salt  increases  the  pala- 
tability.  Varieties  vary  in  the  time  they  require  to 
cook,  and  even  soil  and  climatic  conditions  have  an 
influence.  In  a  floury,  mealy  potato  the  starch  grains 
have  swollen  and  burst,  and  ruptured  the  cell-walls 
surrounding  them,  while  in  a  soggy  potato  this  has 
not  taken  place.  Potatoes  showing  second  growth 
will  not  cook  uniformly;  the  last-grown  portion  will 
cook  first.  When  second  growth'  takes  place  the 
starch  passes  from  the  older  portion  to  the  new;  hence, 
when  cooked,  the  older  portion  appears  to  be  hard  and 
dark,  while  the  newer  portion  is  white  and  floury,  the 
difference  being  due  to  the  presence  or  absence  of 
starch. 


1  wis.   Seventh   Annual  Report,  1S90,  and  Henry,  "  Feeds  and  Feeding," 
p.  212. 


lyo  TH«    POTATO 

Uses. — Potatoes  are  used  as  human  food,  stock  food, 
for  the  manufadlure  of  starch,' syrup,  alcohol,  dextrin, 
etc.  Potatoes  niaj'  be  preserv^ed  as  ensilage^  for  stock 
feeding,  while  the  pomace'  resulting  from  starch  manu- 
fa<5ture  and  potato  feed  '  have  received  attention  for 
the  same  purpose.  Potatoes  may  be  dessicated,  and  in 
this  form  can  be  easily  preser\^ed  in  the  tropics  and 
ar(ftic  regions,  and  thus  furnish  an  excellent  article  of 
diet  in  a  convenient  form  for  transportation.  The  in- 
dustry is  small  at  present,  but  can  be  readily  extended. 


1  U.S.  D.  A.  Div.  of  Chemistry,  Bui.  58. 

2  U.  S.  D.  A.  Farmers'  Bui.  79,  p.  21. 

=>  Me.  Sta   Report,  1S96,  p.  28.    Bui.  65,  p.  115. 
*  Vt.  Bui.  82,  p.  72. 


CHAPTER  XVI 

BREEDING  AND  SELECTION-PROPAGATION  AND 
BREEDING 

Potatoes  are  propagated  from  seed,  cuttings,  lay- 
ers of  green  shoots,  sprouts  from  the  63-68  of  tubers, 
or  portions  of  the  tubers  containing  a  bud  or  eye. 
About  the  beginning  of  the  eighteenth  century  Shirreif , 
of  England,  wrote  that  "  the  potato  is  to  be  considered 
a  short-lived  plant,"  and  that  "  the  onlj-  way  to  obtain 
vigorous  plants  and  to  insure  produdlive  crops  is  to  have 
frequent  recourse  to  new  varieties  raised  from  seed." 
Dr.  Hunter  and  T.  A.  Knight  held  the  same  views. 
T.  A.  Knight  stated  that  late  planting  tended  to  re- 
invigorate  a  degenerating  variety.'  The  value  of  rais- 
ing new  varieties  from  seed  is  recognized  to-day,  and 
for  their  production  some  modern  breeders  selecft  as 
parents  two  varieties,  which  in  most  qualities  bear  close 
resemblance  to  each  other,  avoiding  the  use  of  oppo- 
sites,  the  claim  being  that  it  is  easier  to  fix  the  type. 
Others,  including  Burbank  and  Garton,  make  crosses 
between  widely  divergent  tj'pes,  although  it  takes 
longer  to  fix  the  ones  they  selecft  and  there  is  a  lower 
percentage  worth)'  of  a  trial.  There  is,  however,  more 
chance  of  obtaining  something  above  the  average. 
Wide  crosses  act  upon  the  chara(5lers  in  the  plant  in  a 
manner  similar  to  a  vigorous  push  on  the  pendulum  of 
a  clock — it  goes  higher  on  each  side:  plants  of  higher 

1  Miller's  "Gardeners'    Dictionarj',"   ed.    1807,     "Potatoes."   and  Don's 
"  Gardeners'  Dictionary,"  1S31-3S,  Vol.  IV.,  pp.  400-406. 

171 


172  THE   POTATO 

value  and  plants  of  lower  value  than  either  parent  are 
secured.  A  plant  of  high  value  is  secured  and  grown 
for  a  period  of  j-ears  in  order  to  fix  it.  Those  who 
have  regarded  the  valuable  characfters  which  led  to  the 
selection  of  the  individual  as  fixtures  from  the  beginning 
claim  that  this  period  of  fixing  is  solely  for  the  pur- 
pose of  elimination  of  the  undesirable  characflers,  and 
that  it  ought  to  be  termed  ' '  the  elimination  period  ' ' 
rather  than  ' '  the  fixing  period. ' '  The  interrelationship 
of  different  qualities  is  not  well  known,  but  it  has  been 
noted  that  a  variet}'  having  a  few  thick  stalks  yields 
large  tubers,  but  few  in  number,  while  a  number  of 
weak  stalks  is  often  found  with  a  number  of  small 
tubers.  Early  ripening  and  resistance  to  blight  or  rot 
{P/iytopht/iora  infestans)  are  not  generally  found  to- 
gether. It  is  claimed  that  a  large  produ(5lion  of  seed- 
balls  goes  hand  in  hand  with  a  small  produdlion  of 
tubers.  T.  A.  Knight  claimed  that  varieties  which  did 
not  bloom  readily  could  be  induced  to  do  so  by  removal 
of  the  soil  from  round  the  tuber-bearing  stems,  the  ex- 
planation offered  being  that  the  plant's  failure  in  tuber 
produdlion  would  stimulate  the  production  of  seed.' 

In  pollenizing  varieties  artificially  the  stamens  should 
be  removed  from  the  female  parent  with  fine  pin- 
cers just  as  the  bloom  opens,  or  before,  and  the  flower 
enclosed  in  a  paper  or  gauze  bag.  The  proper  time  to 
apply  the  pollen  is  known  by  the  moist  appearance  of 
the  stigma.  The  pollen  from  the  desired  variety  should 
be  dusted  on  the  stigma  on  two  or  three  successive 
days.     The  bag  may  be  removed  when  the  stigma  dies 


1  Philosophical  Transactions,  1806. 


BREEDING   AND   SELECTION 


173 


and  the  bloom  withers.  The  fruit,  or  seed-ball,  may 
contain  from  100  to  300  seeds.  These  are  washed  from 
the  ripe  seed-balls,  dried,  and  at  the  proper  season 
sown  under  glass,  or  in  a  hot-bed,  or  out-of-doors  in 


FIG.  50 — POTATO  FLOWER,  WITH  CALYX  AND  COROLLA  REMOVED 
On  the  left  are  shown  the  anthers  closed  round  the  pistil.  On  the  right  the 
anthers  are  expanded,  pistil  not  shown  The  inner  surfaces  of  the  anthers 
show  the  line  where  rupture  occurs  when  the  pollen  is  liberated.  Gener- 
ally this  occurs  only  near  the  upper  portion  of  the  anther. 


flats.  The  seeds  germinate  rapidly.  Later  they  are 
transplanted  to  a  well-prepared  piece  of  land  outside. 
The  distance  apart  varies  with  different  growers — from 
12x12  to  26x26  inches,  and  sometimes  more.  The  up- 
right stem  bears  leaves  and  the  axils  of  the  first  leaves 
bear  shoots,  which  turn  downward  into  the  ground 
and  bear  tubers.     The  old  idea  that  the  first  year's 


174 


THE    POTATO 


crop  consist  of  small  tubers,  the  next  larger,  and  so 
on,  does  not  always  hold,  as  a  tuber  weighing  over 
seven  ounces  has  been 
produced  the  first  year. 
The  Burbank  potato  was 
full  size  the  first  year  it 
w^as  grown  from  seed, 
and  many  breeders  feel 
that  unless  the  tubers 
are  of  edible  size  the 
first  year  they  are  not 
likely  to  be  worth  fur- 
ther care.  Frequently 
the  tubers  do  not  reach 
full  size  imtil  the  second 
year.'  The  tubers  from 
each  plant  must  be  kept 
separate,  the  best  seledled 

,       ,  ,  .  ^,  KIG.     51  riSTIL     OK      I'OTATO 

and  planted  again.     The      ,..^^^^,^^^  showing  tmk  parts 

distance  apart  vanes  be-  a_stigma,  where  poUen  is  applied, 
tween     26  X  12    and     40  X    * — style,  down  which  the  pollen  tube 

40  inches.  Wider  plant- 
ing permits  the  study  of 
the  individual.  The 
third,  fourth,  and  fifth 
year  field  culture  is  given, 

and  a  variety  may  be  found  worthy  of  a  name  and 
further  trial  before  distribution.  The  breeder's  aim  is 
to  produce  varieties  which  excel  in  produdlivity, 
power  to  resist  diseases,  earliness,  quality,  percentage 


goes  to  the  ovary,  c.  where  it  fertilizes 
tlie  ovule,  which  become  the  seeds  (see 
Fig.  3<.  d — Attachment  of  stamens, 
removed  to  prevent  self-fertilization. 
^—Petals,  partly  torn  away  to  expose 
ovary.    _/— Sectional  view  of  calyx. 


Minn.  Bui.  Sy,  p.  lo. 


BREEDING    AND    SEL,ECTlON  1 75 

of  starch,  and  have  other  desirable  chara(5leristics — as, 
suitable  shape,  color,  depth  of  eyes,  etc. 

Selection. — Hybridizing  is  of  small  value  unless 
attended  by  careful  seledlion  and  vigorous  elimination 
of  the  poorer  types.  All  potatoes  tend  to  vary  in  cul- 
tivation, either  to  improve  or  degenerate.  This  varia- 
tion is  more  marked  in  some  plants  than  in  others; 
hence,  once  a  variety  is  established,  the  yield  may  be 
materially  increased  and  the  rapid  deterioration  of 
the  variety  prevented  by  selection  of  the  best  plants. 
Seledlion  must  be  made  in  the  field,  not  from  the  bin. 
The  whole  plant  must  be  considered,  not  a  single 
tuber.  Goff'  showed  that  by  perpetuating  the  most 
produdlive  and  least  producflive  plants  of  Snowflake 
potatoes  the  total  yield  of  the  most  produdlive  one  for 
two  years  was  322  ounces,  while  that  of  the  least  pro- 
dudlive was  but  100  ounces,  and,  summarizing  fourteen 
years'  trials,  the  most  produdlive  plants  yielded  180 
per  cent,  more  than  the  least  produdlive.  Bolley,  at 
North  Dakota,  found  that  "equal  weight  pieces  from 
small  or  large  tubers  of  the  same  vine  are  of  equal 
value,  provided  all  are  normally  mature, ' '  ^  confir- 
matory evidence  that  the  whole  plant  is  the  unit  of 
seledlion. 

Growers  may  at  least  maintain  the  produdlivity  of 
their  stocks  of  potatoes  by  careful  seledlion  of  the  best 
plants  when  digging,  careful  storage  of  these  tubers, 
and  then  using  all  of  them  for  seed.  These  might  be 
planted  by  themselves  on  a  piece  of  good  land,  and  se- 


1  (N.  Y.)  Geneva  Report,  1887,  p.  85.     Wis.  Report,  1S99,  p.  306. 

2  N.  D.  Bui.  30,  p.  243. 


176  THE   POTATO 

ledtions  made  from  them  at  the  following  harvest,  the 
best  plants  being  again  retained  for  the  nursery  plat 
and  the  balance  used  as  seed. 

A.  Girard,'  one  of  the  foremost  potato  growers  of 
France,  selecfls  his  potatoes  every  year  from  those 
hills  whose  foliage  is  especially  luxuriant.  He  uses 
the  variety  Richter's  Imperator,  and  prepares  the  soil 
to  a  depth  of  12  to  16  inches,  giving  a  liberal  applica- 
tion of  barn-yard  manure  and  fertilizers,  acid  phos- 
phate, sulphate  of  potash,  and  nitrate  of  soda.  He 
seledls,  for  planting,  tubers  weighing  from  3^  to  4 
ounces.  When  he  cannot  get  such,  he  recommends 
that  tubers  of  7  ounces  in  weight  be  cut  in  two,  and 
tubers  of  io}4  ounces  into  three  pieces — always  cutting 
in  the  diredlion  of  the  greatest  length.  He  insists  on 
the  rejection  of  all  potatoes  weighing  more  than  1 1 
ounces.  If  the  potatoes  available  for  planting  weigh 
less  than  3^  ounces  he  places  in  each  hill  several 
smaller  tubers,  enough  to  bring  the  total  weight  to 
about  4  ounces.  He  lays  great  stress  on  the  distance 
between  the  plants;  the  rows  are  24  inches  apart  and 
the  tubers  are  planted  19  inches  in  the  rows,  these  dis- 
tances having  been  determined  to  be  best  by  careful 
experiment.  He  advises  early  planting,  as  soon  as 
danger  from  frost  is  past.  The  crop  should  be  well 
worked  and  all  potatoes  kept  covered,  and  the  tops  well 
sprayed  with  Bordeaux  mixture,  and  the  crop  not  dug 
until  all  of  the  tops  have  withered.  Farmers  in  the 
co-operative  experiments  under  his  diredtion  report 
yields   of  400  to  700  bushels  per  acre  as  common,  and 

>  E.  S.  R.,  v.,  p.  117. 


BREEDING   AND   SELECTION  1 77 

even  up  to  1,353  bushels  per  acre  with  a  starch  content 
of  20  to  25  per  cent.  One  farmer  secured  almost 
10,000  pounds  of  starch  per  acre,  probably  one  of  the 
largest  yields  of  carbohydrates  ever  obtained  from  an 
acre  of  land. 


APPENDIX 

Spray  Calendar 


Disease 

Spray 

First 

Second 

Third 

Fourth 

Insect 

Mix  lure 

Spraying- 

Spraying 

Spraying 

Spraying 

RKMARKS 

Early 

Bor- 

When 

7  to  14 

7  to  14 

7  to  14 

Blight 

deaux 

plants 

da^'s 

days 

days 

mixture 

are  4  to 

later 

later 

later 

6  in.  tall 

I,ate 

Bor- 

As for 

Up  to  7  spray- 

Blight 

deaux 

early 

do 

do 

do. 

ings  are  some- 

mixture 

blight 

times  given 

Rosette 

Treat  the 
seed 

Flea- 

Bor- 

When 

Repeat 

As  for 

A  deterrent 

beetle 

deaux 
mixture 

beetles 
appear 

if  neces- 
sary 

I  and  2 

only 

Colorado 

Paris 

When 

Repeat 

As  for 

I   pound  Paris 

Potato- 

green  or 

beetles 

if  neces- 

I and  2 

green  per  acre 

beetle 

other 

appear 

sary 

in    100   gallons 

or 

arsenites 

or  more  of  Bor- 

"Bugs" 

in   Bor- 

deaux mixture. 

and 

deaux 

Arsenate  of 

Blister- 

mixture 

lead,  3  pounds 

beetles 

to   50    gallons. 

or  old- 

Arseni  t  e   of 

fashion- 

lead, 3   pounds 

ed  Potato 

to    50    gallons. 

bug 

Green  arsen- 
oid     I    pound 
per  100  gallons. 

Grass- 

Paris 

When 

Repeat 

As    for    C  0 1 0- 

hopper 

green  or 

other 
arsenites 

in   Bor- 
deaux 

mixture 

they 
appear 

it  neces- 
sary 

rado  beetle 

179 


l8o  THE   POTATO 

Seed   Treatment 

Disease  Treatment 

Scab      . Soak   uncut    seed     in     formalin,    i 

pound  to  30  gallons  of  water,  for 
two  hours;  then  dry  and  plant  on 
scab-free  soil. 

Rosette  {Jikizoctonia)        .     As  for  scab. 

Dry  Rot Diseased   tubers    to    be    destroyed; 

those  in  contact  with  them  to  be 
treated  as  for  scab  and  sprayed 
as  for  blight. 

Wet    Rot  (due  to   Blight 

or  Bacteria)  ....  Have  seed  potatoes  in  such  storage 
that  they  can  be  examined,  and 
these  tubers  sorted  out  and  de- 
stroyed. Do  not  plant  affected 
tubers.  Soaking  them  in  forma- 
lin, as  for  scab,  is  advisable  in 
some  cases,  depending  on  the 
cause. 

Stem    Rot    or    Dry    End 
Rot  {Fusariutn  oxyspo- 

rutn) It  attacks  the  stem-end  first;  hence, 

cutting  off  this  end  of  suspected 
tubers  will  reveal  the  disease. 
Discard  diseased  tubers. 


INDEX 


PAGE 

Acid  Phosphate 43,47,119 

Acme  Harrow 23 

Ammonium  Salts  as  Fertilizers    31 

32,  43,  47,  119 

Area  in  Potatoes  in  1899  .  .  153, 156 

in  1903 156 

Arizona  Potato 1 

Arsenate  of  Lead 135,  137 

Arsenical  Poisoning  ....  1'23,  127 

Arsenious  Oxide 136 

Arsenite  of  Lead  ....  135.  137. 138 

Lime 135,  138 

Soda 135 

Available  Phosphoric  Acid    .   .     43 

Bacteria,  Useful 40,  41 

Bacterial  Diseases 122 

Bags 161,  162 

Barium  Arsenite 138 

Barn  Manure  .   .   .  36,37,44,46,119 

Amounts  used 36,  37 

Barrels 162,  164 

Filling 162 

Size  of 162 

Bermuda  Potato 4,  5 

Blacli  Death 135 

Blight,  Early,  or  Leaf  Spot  Dis- 
ease    118,  178 

Late,  or  Rot  .  113,  113-117, 121,  178 

BUster  Beetles 127, 178 

Blooms 4.  5 

Encouraging 172 

Blossoming 16,  172 

Bordeaux    Dust,    or    Dry    Bor- 
deaux   130 

Bordeaux  Mixture  .  115, 116,  118,  12:3 

124,  138,  131 

Benefits  from  Use  of  .  115, 118, 124 

131,  132 

for  Flea-beetles 12:3. 124 

Mixing 129 

Strength  of  Solution 130 

Testing 1.30 

Botany 1-7 

Boxes 163 

Bushel 164, 165 

Breeding 171 

Buckwheat 29 

as  a  Cover  Crop 29 

in  a  Rotation 29 

Bug  Death 135 


PAQE 

Bugs,  or  Potato  Beetle  ...  124, 125 
Bundle  Blackening,  or  Dry  End 

Rot 122, 179 

Bushel,  Weight  of  a 162 

Calcium,  Influence  of  .   .   .    .  35,  36 

Calco  Green 138 

Carbon  Bisulphide 126 

Castor  Pomace 32 

Cellars,  Construction  of  ...   .    149 

for  Storing 149,  150 

Temperature  of 150, 152 

Ventilation  of 150 

Chloride,  Calcium,  injurious  .  .     34 
Chlorides,  Injurious  to  Growth, 

34,43 
Varieties  with  Heavy  Foliage 

Readily  Injured  by 34 

Climate,   Influence  of  .   .8,  66,  111 
Clover,  Value  for  Plowing  Un- 
der    27,  28 

Red 27 

Crimson 27,  28 

Sweet 28 

Clover,  Influence  on  Yield  ...     27 

Cold  Storage 153,  158 

Color  of  Skin 76 

Colorado  Beetle 124,  125 

Commission  Rates 160,  161 

Composition,  Chemical  132,  166, 167 

Intluenced  by  Spraying.  ...    132 

Consumption  of  Potatoes  .  156,  157 

Cooking 169.   170 

Quality 70,  72-74 

Co-operative  Methods  of   Mar- 
keting     160 

Copper  Arsenite 138 

Sulphate 128,  129 

Cottonseed-meal 32,  48 

Cost  of  Selling 161 

Cover  Crops 28,  29 

Cow-peas,  Value   for    Plowing 

Under 27,  28 

Crepidodera  cucumeris,  or  Flea- 
beetle  123 

Crop  Producing  Power  of  Soil 

Reduced 18 

Cultivation     105-109 

Method  of 107 

Tools  Used  In 107 

Cultivations,  Number  of  .  .  105,  106 

181 


I82 


INDEX 


PAGE 

Culture,  Level 107 

Systems  of ii'G 

Cutworms V27 

Darwin's  Potato 1 

Date  of  Planting 96 

Depth  of  Planting 93-96 

Influence  on  Quality 96 

Influence   on   Tuber    Forma- 
tion       94.  95 

Dessicated  Potatoes 170 

Digrestibility  of  Potatoes  ....  16.S 
Diggers,  Mechanical  ....  14-1-146 
Digging  the  Crop 117,  143 

Methods 143,   144 

Di.sease  Resistance  Required  in 
a  Variety 71 

Relation  of  Temperature  to  .       9 
Disease-resisting  Varieties  .  75,  116 

Disk  Harrow 23,  24 

Disparene 135,  137 

Distance  Apart 91-93 

Doryphoru  decemUnvnta,  or  Po- 
tato Beetle 124.   125 

junctn,  or   Southern    Potato 

Beetle 124 

Drainage 17,  116 

Dried  Blood 31 

Drills 106 

Dry  End  Rot 122 

Dry  Rot 122 

Early  Blight 118,   179 

Planting 97 

Ensilage,  Potato '70 

Epicdiita  vitatta 127 

Epiirix    subcrhiata,    or    Flea- 
beetle    124 

Eyes 6 

Depth  and  Frequency  of  .   .  71,  79 
Relation  of  Number  of  Stalks 
Produced  to 62,  63 

Farm  Prices 157,  161 

Feed,  Potato 170 

Feeding  Potatoes  to  Stock  .  168,  169 

Value 168,  169 

Fertilizers 30,31,  37-40 

Amounts  Used 30,  37,  38 

Applying 48 

Compounding 46 

Cost  of 45 

For  Early  Potatoes    ....  35,  39 

Function  of 39-41 

Inoportant  Ingredients  in     .  42,  43 
Influence  of  Period  of  Growth 
Upon  the  Necessary  ....     31 

Mixing 46,  47 

Poor  Mixtures  of 47,  48 

Profit  from  Use  of 37,  38 


PAOE 

Fertilizers.  Purchasing  .  42,  43,  44, 45 
Value  of  Home  Mixing  of  .  .  46 
Valuable  .  .37,  38,  40,  176, 177 

Valuing 39,40,43-46 

Fixing  New  Varieties    .....    172 

Flavor 60,  74 

Flea-beetle 83,114,118,123 

Punctures  Injurious  .   .  82, 114, 118 

Flowers 3,  5 

Formalin 69. 118,  119, 128 

Too  Strong  a  Solution  Injuri- 
ous       69 

Fungicides 128 

Eiisarinm  oxysporum    .   .   .  122,  179 

(lelechin  Operrulclla  Zell.,  Po- 
tato Worm  125,  126 

Good  Roads,  Value  of  .   .   .  158,   159 

Grading  Potatoes 162 

Grasshoppers 126 

Green  Arsenite 135 

Green  Arsenoid 135,  138 

Growth,     Conditions    Influtnc- 

ing 8,  16,  30 

Effect  of  Chlorides  on  ...   .     34 
Influence  of  Dry  Weather  on  .       9 

Manuring 30 

Influence  of  Respiration  on  .       9 
Influence  of  Time  of,  on  Fer- 
tilizing       31 

Obstructions  to Ill,  127 

Period  of 14,  31 

Habitat  of  Potato 1 

Hammond's  Slug  Shot 135 

Harrow,  Acme 23 

Disk 24 

Spike-tooth 107 

Spring-tooth 23,  34 

Harrows,  Action  of,  on  the  Soil    24 

Harvesting 143 

Methods  of 143 

Hauling  Farm  Produce  .   .    158. 159 

Cost  of 1.58. 159 

Haulm       34,71,80,81 

Hellebore 135 

Hilling 14,  16 

Time  of 16 

Hills 106 

Humus,  A  Food  for  Bacteria  .   .     41 
Effects  on    Physical    Proper- 
ties of  the  Soil 23 

In  Soils 21,41,42 

Influence  of  Tillage  on  ...   .    105 

Influence  on  Depth  of  Plowing    21 

Influence  on  Soil  Moisture  .   .     23 

Hybridizing 171-173 

Imports  of  Potatoes 157 


INDEX 


183 


PAGE 

Insecticides 135, 136 

Insuluble  Phosphate  of  Lime    .     43 
Introduction  into  Virginia  ...       2 

into  Europe 3,  7 

Irrigation,    Amount   of    Water 

Used  in 48,  49 

Dangers  of 49 

Value  of 48,  49 

June  Bug 136 

Kainit 43,48,119 

Kno-bug 1.3.5 

Lachnosterna 126 

Late  Planting 97 

Laurel  Green 13.5,  138 

Leaf 71,81,83,114,131,133 

of  Rust-resistant  Varieties  of 
Wheat 83 

Spot  Disease,  or  Early  Blight 

118,  178 

Value  of  a  Tough,  Hard  .   .    81,83 
Level  Culture 106,  107 

Objections  to 106 

Light,  Influence  on  Yield    ...       8 
Lime 35,36,41,119,138 

Uses 41, 128 

Liming     31.  .32 

London  Purple 135 

Loss  of  Potatoes  in  Storage  151,  1.52 


Macrosporium  solani.  or  Early 

Blight 118,  178 

Manure 30,  36,  37,  44 

Amounts  Applied 36,  .37 

Influence  of 30 

Value     44-46 

Manuring.  Reasons  for ^0 

Marketing,  Cost  of 160,161 

Markets 1.57,  158 

Distant 1.57,  160 

Local 1,59, 161 

Maturity,  Time  of 71,79,80 

Melimnplus  sp 126 

Mexican  Potato 1 

Moisture,  Conservation  of  Soil,  22, 23 

Influence  of 8,  9 

Mulch,  Soil 106,  109 

Mulching 110 

Nitrate  of  Soda  .   .   .  31,  32, 42.  47,  48 

Effect  on  Buds 69 

Nitrates 42 

Nitrogen 30,  31,42 

Effect  of  Excess 31 

Influence  of 31 

Occurrence  in  Fertilizers  .   .     42 


PAGE 

Nitrogen  of  Barn  Manure  ...  86 
Requirement  while  Young  .  .  31 
Sources  of 31,  42 

Nozzles 141,142 


Organic  Nitrogen  of  Fertilizers    42 
Oospora  scabies  (Thax.;,  Scab, 

119,  121 

Packages 161 

Paragrene 1:3.5, 1.38 

Paris  Green  .   .  124, 125,  137,  135.  136 

Amount  to  use 125,  127 

for  Flea-beetles 124 

for  Potato  Beetles 135 

Peas  in  Rotation !>7 

Phosphatic  Fertilizers  .  35,  43,  43,  47 

Effect  on  Maturity 35 

Phosphoric  Acid,  Influence  of  .     35 
Phytophthora  infestans.  Blight 

or  Rot 112-117, 121 

Pits 147-149 

Pimply  Potatoes 124 

Pink  Arsenoid 135,  137 

Planters 100-104 

Hand 100,  101 

Horse loi- 104 

Planting,  Date  of 96,  97 

Depth  of 14,  93-96 

Distance  Apart 91-93 

Early  and  Late 97 

Hand 59.  97-100 

Influence  of  Depth  on  Depth 

at  which  Tubers  Form  .   .    94-96 
Influence    of     Depth    of,    on 

Quality % 

Methods  of 59,  97-100 

Plow,  Potato  or  Shovel 144 

Plowing 21-23 

Conditions  Governing  .   .   .  21,22 

Deep 21,42 

Depth  of 21,22 

Fall .     21 

Plowing,  Spring 22 

Pollen 3,  173 

Pollenizing     '  172 

Pomace,  Potato 170 

Potash,  Amounts  Applied  .   .  35,  38 

Influence  of 31 ,  3:3 

on  Leaves .32 

on  Quality 33,  34 

on  Roots .33,  33 

on  Starch  Formation    .   .  .33,  34 

on  Tubers    .   . 32,  33 

Muriate  of  ...   .  :33,  .34,  38,  43,  119 

Amounts  Used 38 

Sources  of 33 

Sulphate  of    ...   .  33,  34,  43,  119 

Potassic  Fertilizers 43 

Potassium  Ferro-Cyanide    ...    130 

Potato  Beetle 124,  ]25 

Bug,  Old  Fashioned  .   .   .  137,  178 


184 


INDEX 


PAGE 

Potato,  seed 5,  6,  ir3 

Stalk  Weevil 126 

Worm 125,  126 

Preparation  of  Land 21-23 

Pressure  Required  for  Spraying.  140 

Prices,  Average 153 

Farm 157 

in  Eastern  and  Central  States .  159 

Production 153-157 

Propagation 171 

Pumps 140 

Quality,  Cooking 70 

Influence  of  Depth  of  Tubers 

ou 96 

Quick  Death 136 

Rainfall,  Amount  Sufficient .  48,  49 

Rape  as  a  Cover  Crop 29 

Respiration 9,  10, 152 

Influence     of      Temperatore 

on 9,  10 

Rhizoctoniasolani 118,  179 

Roads 158 

Roots C,  10,  55 

Cho.racterof 11,14,15 

Depth  of 11,14,  15 

Effects  of  Tillage  on 14 

Rosette  Disease 118,  179 

Rot,  or  LateBlight  .  112,  113-117,  121 
Rotation  .  26-29, 110, 118, 119, 121, 127 

Factors  in 26,  27,  50 

Five-course 26 

Four-course 26 

Leguminous  Crops  in  a    .   .  27,  28 

Maine 26 

Ohio 27 

Three-course 36 

Rust-resistant      Varieties       of 

Wheat 82 

Rye 27-29,  120 

Sack-holder 162 

Sacks,  Costof 161,162 

Scab 119,  121 

Scheeles  Green 135 

Season,  Influence  of 66,  111 

Second  Growth 12,  85 

Seed 5,  6,  173 

Amount  per  Acre 63,  64 

Bud.  Stem  Ends,  and  Middles.    66 

Cost  of 64 

Cutting 60 

Effect  of  Insufficient  Amount.  104 
Importance  of  a  Good  Strain 

of 51,53 

Proper  Storage  of  ....    52,  53 

Selection 52,  74, 175 

Influence  of  Altitude     ....     52 
Management      Previous      to 
Planting 53 


PAGE 

Seed,  Methods  of  Storing  .  .  53,  54 
Northern  and  Southern  ...  51 
Relation  of  Number  of  Stalks 

to  the  Eyes  on 62,  63 

Relation  of  Weight  to  Viabil- 
ity of  67 

Single  Eyes 62,64 

Size  of 61-65,  67, 175 

Source  of 51 

Sprouting 53-60 

Time  to  Cut 61 

Treatment  for  Diseases    .   .   .    179 
Uses  of  Second  Crop  for     .  52,  53 

Viability  of 66,  69 

Whole  and  Cut     60-63,  65 

Seed-balls 1,5, 173 

Selection 52, 175 

Shape  of  Tuber 5,71,76 

Shovel,  Potato 147 

Sizeof  Tubers,  Variation  in    .   .      75 

Skin 5,  71,78, 120 

Color  of 76 

Cracked 84 

Desirable 78 

Soil  Moisture,  Conservation  of 

22  23 

Soils 17-25,153 

Changes  in 41 

Chemical     Composition    and 

Crop  Producing  Power  of  .  30 
Composition  of  New  York  .  39 
Diminished    Crop    Producing 

Power  of 18 

Ingredients  Removed  by  Pota- 
toes from 39, 40 

Preparation  of 21-23 

Relationship  of  Varieties  to  19,  87 

Sandy  Loam 17 

Solanum  commersoni 1 

Solannm  jamesii 1 

maglia 1 

tuberosum ...    1,3 

var.  Boreale 1 

Soluble  Phosphate  of  Lime   .  .      43 

Sorters,  Mechanical 162 

Specific  Gravity  of  Tubers     .   .    167 

Spray  Calendar 178 

Spraying  Attachments    .   .    140,  141 

Cost  of 139 

Effect  on  Yield    .   .       .   .    132,  134 

Hose 141 

Spraying,  Machines 140 

Nozzles 141,  143 

Pressure  Required  for  ....    140 

Profits  from 139 

Pump 140 

Tanks 141 

Time  of 134 

Sprayings,  Number  of  .  .  .  134,  135 
Sprays  and  Spraying  .  .  .  128-142 
Spring-tooth  Harrow  ....  23,  24 
Starch  .31,  72,73,  78,  132,  167,  170,  177 
Content  and  Speciflc  Gravity  .  167 


INDEX 


185 


PAGE 

Starch,  Distribution  in  the  Tuber 

„    ,  "2, 73,  rs 

Production 31,  132,  177 

Stem  Rot 122,  I79 

Storage 52,   143-152 

in  Cellars 149,  150 

'n  Pits   147-149 

Losses  in 143,  151,  152 

Temperature  for    .   .  ."3.   151,   152 

Striped  Blister  Beetle 127 

Subsoiling 20    21 

Sulphur '120 

Sun  Scald .111 

Sweet  Clover  as  a  Green  Manure,    28 

Tanks 141 

Tile  Drainage 17 

Tillage 14,  42, 105, 10(5,  109 

Deep 14 

Objects  of '    106 

Shallow 14,  195,  109 

Value  of 42 

Tip  Burn .  m,  112 

Tobacco  Leaf  Miner  ....  125,'  126 
Tools  for  Cultivation  ....    107-109 

Surface-fitting 23 

Tomato  Worm 127 

Transportation,  Cost  of  .   .  159 

by  Rail 159 

by  Road l.-,8,  159 

by  Water 159 

Trays 54,  60 

Trichobaris  trinotata 126 

Tuber  Formation    .    6,  16.  .54.  .55,  94 
^       ,  95.' 172 

Depth  of 54,  ,55,  94.  95 

Retarding  of 172 

Stimulation  of  ...   .  .54    55 

Tubers,  Hollow '74 

Number  Formed  by  a  Plant  '.     74 

Rate  of  Growth  of I6 

Size  of  Seedling 173.  174 

Type,  Varieties  Not  True  to  .  72,  85 


Unit  Value  of  Fertilizers  ....     44 
Uses  of  Potatoes ^70 

Value  per  Acre 153 

Varieties   .   .  19,  51.  72,  75,  76,  a3-90 

u       A-       X.  171-174 

Breedmg  New 171-174 

Disease-resisting 76 


PAGE 

Varieties.  Duplication  and  Re- 
naming of 85, 86 

Fixing  New 170 

Importance  of  New '.    171 

Improvement  in g4 

Influence  of  Soil  and  Condi- 
tions on 19,  87 

Influence  of,  on  Yield    .    .   .   .   '  75 

Life  of  Modern 83 

Life  of  Older 83  84 

List  of 88^90 

Most  Popular 87-90 

Staying  Power  of  ...   .  83 

Testing §6 

True  to  Name 85 

True  to  Type 72 

Variety.  Selecting  a 70-90 

Variation  in  the 52-54 

Viability  of  Tubers  .   .   .   .  66-69 

Vigor  of  the  Plant  .   .    7l,  82-85,  118 
Indications  of  Deficiency  in  .  84, 85 

Washing  Soda  and  Copper  Sul- 
phate Mi.xture  131 

Water,  Available 43 

Requirement 33.  48-50 

Efl'ect  of  Fertilizers  on  33 

Per  Pound  of  Dry  Matter    .     50 

Weeder 193 

Weeds,  Injurious 105 

Wet  Rot 121   122 

Whale  Oil  Soap 136 

AVheat,  Depth  at  which  Roots 

Form 15 

Varieties  Resistant  to  Rust  .     82 
White  Arsenoid    ....  1.33 

Wild  Potato ;   ;       1 

Wireworms '    127 

Wood  Ashes 43,119 


Yield  .  .  7,  14,  26-28,  70,  74,  75,  84,  87 
132,  134,  1.53 

Average 74, 153 

Eflfects  of  Sprouting  Upon  .  .  58 
Influence  of  a  Crop  of  Clover 

on 27,28 

Influence  of  Light  Upon  ...  8 
Influence  of  Soil  on  .  .  .  19,  20,  87 
Influence  of  Spraying  on  ,  1.32,  134 
Influence     of      the     Variety 

Upon 19,  20,  75,  87 

Maximum 74 


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RECENT  BOOKS  BY  THOMAS  SHAW 

Professor  of  Animal  Husbandry  at  the  University  of  Minnesota, 
formerly  Professor  of  Agriculture  at  the  Ontaiio  agricultural  College. 

Animal  Breeding 

The  most  complete  and  comprehensive  work  ever  published  on  the 
subject  of  which  it  treats,  and  the  first  book  of  the  kind  ever  given  to 
the  world  which  has  systematized  the  subject  of  animal  breeding. 
The  striking  originalitj'in  the  treatment  of  the  subject  is  no  less  con- 
spicuous than  the  superb  order  and  regular  sequence  of  thought  from 
the  beginning  to  the  end  of  the  book.  Illustrated.  5x8  inches,  13 
full-page  plates,  about  400  pages.    $1.50. 

The  Study  of  Breeds 

origin,  history,  distribution,  characteristics,  adaptability,  uses,  and 
standards  of  excellence  of  all  the  pedigreed  breeds  of  cattle,  sheep, 
and  swine  in  America.  The  accepted  text-book  in  colleges,  and  the 
authority  for  farmers  and  breeders.  3S7  pages,  5x8  inches,  60  full- 
page  plates,    f  1.50. 

Forage  Crops  Other  than  Grasses 

How  to  cultivate,  harvest,  and  use  them.  Indian  corn,  sorghum, 
clover,  leguminous  plants,  crops  of  the  brassica  genus,  the  cereals, 
millet,  field  roots,  etc.  Intensely  practical  and  reliable.  295  pages. 
Illustrated.    5x8  inches,    f i.oo. 

Soiling  Crops  and  the  Silo 

The  growing  and  feeding  of  all  kinds  of  soiling  crops,  conditions  to 
which  they  are  adapted,  their  plan  in  the  rotation,  etc.  Best  methods 
of  building  the  silo,  filling  it,  and  feeding  ensilage.  Illustrated. 
5x8  inches,  378  pages.    I1.50. 


Swine  Husbandry 

By  F.  D.  CoBURN.  New,  revised,  and  enlarged  editition.  A  practical 
manual  for  the  breeding,  rearing,  and  management  of  swine,  and  the 
prevention  and  treatment  of  their  diseases.  In  preparing  this  work 
it  has  been  the  object  of  the  author  to  condense  in  one  volume,  from 
all  available  sources,  the  ideas  and  conclusions  of  the  most  practical, 
successful,  and  observant  men  who  have  followed  the  business  in  our 
time,  and  in  our  own  country,  acting  upon  the  belief  that  no  one 
man,  or  any  half-dozen  men,  know  all  there  is  worth  knowing  on  a 
subject  so  extensive  and  important  as  that  of  Swine  Husbandry.  It 
is  the  fullest  and  freshest  compendium  relating  to  swiue  breeding  yet 
offered.    Cloth,  i2mo.    Illustrated.    I1.50. 

Home  Pork  Making 

The  art  of  raising  and  curing  pork  on  the  farm.  By  A.  W.  Fulton. 
A  complete  guide  for  the  farmer,  the  country  butcher,  and  the 
suburban  dweller,  in  all  that  pertains  to  hog  slaughtering,  curing, 
preserving,  and  storing  pork  product — from  scalding  vat  to  kitchen 
table  and  dining-room.     Fully  illustrated.     Cloth.    50  cents. 

Shepherd's  Manual 

By  Henry  Stewart.  A  practical  treatise  on  the  sheep  for  Ameri- 
can farmers  and  sheep-growers.  The  results  of  personal  experience 
of  many  years  with  the  characters  of  the  various  modern  breeds  of 
sheep,  and  the  sheep-raising  capabilities  of  the  United  States  and 
Canada — and  the  careful  study  of  the  diseases  to  which  ovir  sheep  are 
chiefly  subject,  with  those  by  which  they  maj'  eventually  be  afflicted 
through  unforeseen  accidents — as  well  as  the  methods  of  management 
called  for  under  our  circumstances,  are  here  gathered.  Illustrated. 
Cloth,  i2rao.    $1.00. 

Cabbage,  Cauliflower,  and  Allied  Vegetables 

By  C.  I,.  Allen.  A  practical  and  reliable  guide  to  the  successful 
raising  of  cabbage,  cauliflower,  broccoli,  collards,  Brussels  sprouts, 
kale,  and  kohlrabi,  from  "  seed  to  harv'est."  Illustrated.  5x8  inches, 
128  pages.     Cloth.     50  cents. 

Hedges,  Windbreaks,  Shelters,  and  Live  Fences 

By  E.  P.  Powell.  The  planting,  growth,  and  management  of  hedge 
plants  for  countrj'  and  suburban  homes.  Illustrated.  5x8  inches, 
140  pages.    Cloth.    50  cents. 

Landscape  Gardening 

By  F.  A.  Waugh.  a  treati.se  on  the  general  principles  governing 
outdoor  art,  with  sundry  suggestions  for  their  application  in  the 
commoner  problems  of  gardening.  Illustrated.  5x8  inches,  150  pages. 
Cloth.    50  cents. 

Plums  and  Plum  Culture 

By  Prof.  F.  A.  Waugh.  A  complete  manual  for  fruit-growers, 
nurserymen,  farmers,  and  gardners,  on  all  known  varieties  of  plums 
and  their  successful  management.  A  monograph  of  the  plums  culti- 
vated in  and  indigenous  to  North  America,  with  a  complete  account 
of  their  propagation,  cultivation,  and  utilization.  It  is  one  of  the 
most  complete,  accurate,  and  satisfactory  works  ever  written  for  the 
field  of  American  horticulture.  Illustrated.  5x8  inches,  371  pages. 
Cloth.    1 1. 50. 

Hemp  (Cannabis  sativa) 

By  S.  S.  BoYCE.  A  practical  treatise  on  the  culture  of  hemp  for  seed 
and  fiber,  with  a  sketch  of  the  history  and  nature  of  the  hemp  plant. 
All  the  various  operations  connected  with  hemp  culture  are  so  plainly 
and  clearly  described  as  to  enable  any  one  to  make  a  success  of  hemp- 
raising.    Illustrated.    5  x  8  inches,  122  pages.    Cloth.    50  cents. 


Ginseng— Its  Cultivation,  Harvesting,  Marketing,  and  Mar- 
ket Value. 

By  Maurice  G.  Kains,  with  a  short  account  of  its  history  and  bot- 
any. It  discusses  in  a  practical  way  how  to  begin  with  either  seed  or 
roots,  soil  chmate  and  location,  preparation,  planting  and  mainte- 
nance of  the  beds,  artificial  propagation,  manures,  enemies,  selection 
tor  market  and  for  improvement,  preparation  for  sale,  and  the  profits 
that  may  be  expected.  The  booklet  is  concisely  written  well  and 
profusely  Illustrated,  and  shouU  be  in  the  hands^of  all  who  expect 
n°rJi?.hV''''/''?^  *.°  supply  the  export  trade,  and  to  add  a  new  and 

wi?h  the  re^nlfr'S'nl.  "'"''  ^^"°"  ^"^.  «^^'"'^"'^'  ^i'^^o^t  interfering 
witn  tne  regular  work.    i2mo.    35  cents. 

Land  Draining. 

^L^}-^^^}' J^^^^^^-  A  handbook  for  farmers  on  the  principles  and 
f=,v^!l'' k'?'^  draining,  giving  the  results  of  his  extended  expeSence"n 
laying  tile  drains.  The  directions  for  the  laying  out  and  the  con 
struction  of  tile  drains  will  enable  the  farmer  to  avoid  the  errors  of 

Practical  Forestry. 

?L"^^' u'^^T-  ^-  J^'^LLER.  A  treatise  on  the  propagation,  planting 
name<"o/I?l".°v,"'  ■^')>'^  descriptions  and  the  botanilal  and  popula? 
names  of  all  the  indigenous  trees  of  the  United  States  and  notes  on 
a  large  number  of  the  most  valuable  exotic  species.    $150 

Mushrooms.     How  to  Grow  Them. 

By  William  F.^lconer.  This  is  the  most  practical  work  on  the 
subject  ever  written,  and  the  only  book  on  growing  mushrooms  nub 
''^Sl'^  '"  America.  The  author  describes  how  he  Irows  mCXooms 
and  how  they  are  grown  for  profit  by  the  leading  marlet  garfenerl" 
and  for  home  use  by  the  most  successful  private  groweri  Sra' 
vings  drawn  from  nature  expressly  for  this  work.    Clorh.    Ji.S!^ 

The  Propagation  of  Plants. 

By  Andrew  S.  Fuller.  Illustrated  with  numerous  eneravino-s 
hvhWH-"^""^'  Poetical  and  useful  work.  DescribitS  the  pfocess^of 
hybridizing  and  crossing,  and  also  the  many  different  modes  bv 
Tsmo      $150^  ^^     '^'  "^^^  ^^  propagated  a/d  multfplie^    cioth^ 

Silos,  Ensilage,  and  Silage. 

By  Maxly  Miles,  M.D.,  F.R.M.S.  A  practical  treatise  on  the  ensi 
^f  H^n  ^°'^'^?{;  ■^°''-"-  Containing  the  most  recent  and  authentic  in"o,^ 
cents  important  subject.     Illustrated.     Cloth.   i2mo     50 

Play  and  Profit  in  My  Garden, 

^■u  ^'  ■^-  ^'^^-  ■  The  author  takes  us  to  his  garden  on  the  rockv  hit! 
sides  in  the  vicinity  of  West  Point,  and  shows  us  how  out  of Taf  er 
four  years- experience,  he  evoked  a  profit  of  «,  000  and  this  while 
carrj^ing  on  pastoral  and  literary  labor.  It  Ts  Wy  rarelv  th^t  so 
much  literary  taste  and  skill  are  mated  to  so  much^agricuUural  ex° 
penence  and  good  sense.    Cloth,  i2mo.    f  i.oo.  agricultural  ex- 

Grape  Culturist. 

By  AXDREW  S.  Fuller.  This  is  one  of  the  very  best  of  work-snn 
nen?«"7^  °^  the  hardy  grapes,  with  full  direct^ns  for  alT depart- 
ments  of  propagation,  culture,  etc..  with  150  excellent  eneravinS 
Illustrating  planting,  training,  grafting,  etc.^  Cloth.  i2mofi  50 ^^^' 


Fumigation  Methods 

By  Willis  G.  Johnson.  A  timely  up-to-date  book  on  the  praiftical 
application  of  the  new  methods  for  destroying  insedts  with  hydro- 
cyanic acid  gas  and  carbon  bisulphid,  the  most  powerful  inse<5ticides 
ever  discovered.  It  is  an  indispensable  book  for  farmers,  fruit  grow- 
ers, nurserymen,  gardeners,  florists,  millers,  grain  dealeis,  transpor- 
tation companies,  college  and  experiment  station  workers,  etc.  Illus- 
trated.   313  pages.    5x7  inches.     Cloth.     $1.00. 

Alfalfa 

By  F.  D.  COBURN.  Its  growth,  uses,  and  feeding  value.  The  fa<5l  that 
alfalfa  thrives  in  almost  any  soil  ;  that  without  reseeding,  it  goes  on 
yielding  two,  three,  four,  and  sometimes  five  cuttings  annually  for 
Hve,  ten,  or  perhaps  100  years  ;  and  that  either  green  or  cured  it  is 
one  of  the  most  nutritious  forage  plants  known,  makes  reliable  infor- 
mation upon  its  production  and  uses  of  unusual  interest.  Such  in- 
formation is  given  in  this  volume  for  every  part  of  America,  by  the 
highest  authority.  Illustrated.  164  pages.  5x7  inches.  Cloth.  50 
cents. 

Coburn's  Swine  Husbandry 

By  F.  D.  CoBURN.  New,  revised,  and  enlarged  edition.  The  breed- 
ing, rearing,  and  management  of  swine,  and  the  prevention  and 
treatment  of  their  diseases.  It  is  the  fullest  and  freshest  compen- 
dium relating  to  swine  breeding  yet  offered.  Illustrated.  312  pages. 
5x7  inches.    Cloth.    I1.50. 

The  Cereals  in  America 

By  Thom.\s  F.  Hunt,  JM.S  D.  Agr.,  Professor  of  Agronomy  in  Col- 
lege of  Agriculture,  Cornell  University.  This  is  primarily  a  text-book 
on  Agronomy,  but  is  equally  as  useful  to  the  farmer  as  to  the  teacher 
or  student.  It  is  written  by  an  author  than  whom  no  one  is  better 
qualified  The  subject-matter  includes  an  accurate,  comprehensive, 
and  succintft  treatise  of  wheat,  maize,  oats,  barley,  rye,  rice,  sorghum 
(Kafir-corn),  and  buckwheat,  as  related  particularly  to  American  con- 
ditions. The  author  has  made  a  comprehensive  study  of  the  topics 
treated,  drawing  freely  from  the  publications  of  the  United  States 
Department  of  Agriculture,  American  Experiment  Stations,  and  rec- 
ognized journals  related  to  agriculture.  First-hand  knowledge, 
however,  has  been  the  policy  of  the  author  in  his  work,  and  every 
crop  treated  is  presented  in  the  light  of  individual  study  of  the  plant. 
Illustrated  with  100  entirely  new  and  original  drawings  by  C.  W. 
Furlong  and  A.  K.  Dawson.  "450  pages.    5^4x8  inches.     Cloth.    ^1.75. 

Fruit  Harvesting,  Storing,  Marketing 

By  F.  A  W.AfGH.  A  pracflical  guide  to  the  picking,  storing,  shipping, 
and  marketing  of  fruit.  The  principal  subje<5ts  covered  are  the  fruit 
market,  fruit  picking,  sorting  and  packing,  the  fruit  storage,  evapo- 
rating, canning,  statistics  of  the  fruit  trade,  fruit  package  laws,  com- 
mission dealers  and  dealing,  cold  storage,  etc.,  etc.  No  progressive 
fruit  grower  can  afford  to  be  without  this  most  valuable  book.  Illus- 
trated    232  pages.    5x7  inches.    Cloth.    $1.00. 

The  American  Sugar  Industry 

By  Herbert  Mvrick.  A  pracftical  manual  on  the  production  of 
Sugar  Beets  and  Sugar  Cane,  and  on  the  nianufa<5ture  of  Sugar  there- 
from. A  handbook  for  the  farmer,  manufacturer,  statesman,  or  stu- 
dent. This  book  is  the  only  complete,  up-to-date  epitome  of  this  new 
and  promising  industry.  It  covers  just  the  points  that  every  one  in- 
terested wants  to  know  about.  It  illustrates  and  describes  the  newest 
model  sugar  mills.  It  gives  the  results  of  the  latest  experience  in 
promoting  and  operating  sugar  factories.  It  shows  just  how  to  estab- 
lish the  industry  in  any  given  locality.  Illustrated.  10x7  inches. 
240  pages.    Cloth.    I1.50. 


Farmer's  Cyclopedia 
of  Ag(riculture 

A  Compendium  of  Agricultural  Scie?tce  a?id  PraSlice 
on  Farm,  Orchard  and  Garden  Crops,  and  the 
Feeding  and  Diseases  of  Farm  Animals 

'By    EARLEY  VERNON  WILCOX,   Ph.D. 
and  CLARENCE   BEAMAN  SMITH,    M.S. 

Associate  Editors  in  the  Office  of  Experiment  Stations,   United  States 
Depariment  of  Agriculture 


THIS  is  a  new,  practical,  and  complete  pres- 
entation of  the  whole  subject  of  agricul- 
ture in  its  broadest  sense.  It  is  designed 
for  the  use  of  agriculturists  who  de- 
sire up-to-date,  reliable  information  on 
all  matters  pertaining  to  crops  and  stock,  but 
more  particularly  for  the  actual  farmer.  The 
volume  contains 

Detzuled  directions  for  the  culture  of   every 
important    field,    orcheo-d,    and    gz^-den    crop 

grown  in  America,  together  with  descriptions  of 
their  chief  insect  pests  and  fungous  diseases,  and 
remedies  for  their  control.  It  contains  an  ac- 
count of  modern  methods  in  feeding  and  handling 
all  farm  stock,  including  poultry.  The  diseases 
which  affect  different  farm  animals  and  poultry 
are  described,  and  the  most  recent  remedies  sug- 
gested for  controlling  them. 

Every  bit  of  this  vast  mass  of  new  and  useful 
information  is  authoritative,  practical,  and  easily 
found,  and  no  effort  has  been  spared  to  include 
all  desirable  details.  There  are  between  6,000 
and  7,000  topics  covered  in  these  references,  and 
it  contains  700  royal  8vo  pages  and  nearly  500 
suberb  half-tone  and  other  original  illustrations, 
making  the  most  perfect  Cyclopedia  of  Agricul- 
ture ever  attempted. 

Handjomely  bound  in  cloth.  ^3. SO;    half  morocco 
{•Very  jumpiuouj^.  ^4.50,  postpaid 

RDAUPr      Minn     OnUDAUV       52  Lafayette  Place.  New  York,  N.  Y. 
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CONTAINING  }00  Svo  PAGES,  PROFUSELY 
ILLUSTRATED,  AND  GIVING  FULL  DE- 
SCRIPTIONS    OF   THE   BEST    WORKS   ON 


THE  FOLLOWING  SUBJECTS      :     ■•     ■■     ■•    ■• 

Farm  and   Garden 

Fruits,   Flowers,   etc. 

Cattle,   Sheep  and   Swine 

Dogs,    Horses,   Riding,   etc. 

Poultry,   Pigeons   and   Bees 
Angling  and   Fishing 
Boating,   Canoeing  and   Sailing 
Field  Sports  and  Natural  History 

Hunting,   Shooting,   etc. 

Architecture   and  Building 

Landscape   Gardening 

Household  and   Miscellaneous 


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LIBRARY. 

DiDision  of  Horticulture, 


